Share your tower defense angst with the world

[cliffski]

Sooo... my current project has a very strong Tower-Defense vibe about it (although with lots of other stuff), and although I have played a lot of games in that genre, there is a lot of gameplaying experience here, and I wondered what the consensus was on...


What absolute must-haves there are in a tower defense game for you to enjoy a title in the genre

What things do TD games do that irritate you?


For example:
I've always been bugged by TD games that start really horribly slowly, with units that proceed at a snails pace. I hate games in general where you can't zoom in and (massively) out, so that's something I assume is a must.
The idea of a first person tower defense game just confuses me. That seems like making a turn-based version of tetris to me, but YMMV.

If money and time was no object, what would the ultimate tower defense game have? I notice few if any have any mod support.

For me, TD is about nervousness. Concern that the forces that you have are not going to quite hold out aginst the forces coming your way. It's a game based on uncertainty and the battle being a 'damn close run thing'. Plus the slight panic of making decisions against the clock. (I rarely pause TD games). Am I in the majority there? Or do people treat them as very clinical puzzle games?

[Razgon]

I love the way Defense Grid handles its setup, in that you don't get the first wave before you put down the first tower.

I also dislike the newfangled "You are a person that can move around on the gameboard" thingie that many new TD games come with.

I love the way that speed isn't essential in TD games like Defense Grid, but you have time to plan and execute your moves, but also have the option of speeding up gameplay if you are all set to go.

Basically, if you want my take on a perfect execution of a Tower Defense game, look at Defense Grid - simply beautifull

*disclaimer - I have NOT played your game, Cliffski - sorry

[Nathan Phoenix]

I don't like MOST tower defenses that make you a person that moves around the board, yet Pixeljunk Monsters is my favorite TD ever, by far. I'm not a huge fan of directly attacking with your avatar, but gathering, building, upgrading, etc is cool.

I feel that towers must be upgrade-able with clearly defined benefits. In fact all towers should be clearly defined what they are good at from the beginning. This seems obvious but I've played a few where you just have to learn as you go.

I don't like ones where you get to manually send each wave in. That's too easy. Time should be a resource that adds to the intensity, so wave pacing is important to tune.

[Ergryspeerdt]

I used to play a lot of WC3 TD (the only good part of WC3). I've played a handful of tower defence games since then and the things that have bothered me are:



Multiplayer is essential, it's just not interesting enough to me otherwise. It was always something I did with my friends.
If I can't manipulate the paths of the creeps I'm not interested.

[Houngan]

One thing, and this applies in general to most any progressive video game, is that I want to have periods where I'm overpowered and periods where I'm trying to catch back up. I don't like games where the nervousness you cite is constant throughout. When I finally get enough money to upgrade my Super Monkey Tower or whatever then I want a few rounds where I'm sitting back and cackling at the destruction.

H.

[slantz]

I'm not a fan of TD games that require you to build a maze out of your towers, like Desktop Tower Defense. I've found games like that devolve into path juggling to win, which tends to trivialize the need to be smart with the actual towers.

I personally like persistant upgrades, ala Defender Chronicles, but I've also heard people complain (validly) that grinding=success in those games. But for me, it tends to provide longer-term goals and more replayability. Star Defense Mission is just another cheap badly-translated TD game, but its persistant meta-game tech tree has me playing far more than the game otherwise should.

I like games like Defender Chronicles, PvZ, Tiny Heroes, Anomoly, and others that break the mold a bit. Their variety doesn't necessarily make them better-designed games, but it does help them stand out in a crowded market, and tends to increase the novelty of playing them.

Please, please make sure your game clearly describes what things do. Not only the towers themselves, but also any branching upgrades. Star Defense Mission is a great example where they only have 3 towers, each with 2 branching upgrade paths, and I still have no idea what all the upgrades do.

And along similar lines -- numbers please. Generally TD games are balanced such that upgrades are more cost efficient than new towers, or the other way around. One or the other. But without any numbers to go on, I have no idea how to make educated decisions about things like tower range (especially after upgrades are applied), damage efficiency, utility efficiency, etc.

[cliffski]

Interesting to hear dislike for the controlling-one-dude-in-the-middle mechanic. I strongly dislike that too.
There are a lot of conventions that exist in TD that people never try to play with or break. For example:
waves: Why do the creeps have to attack in distinct waves? Isn't that a bit arbitrary?
upgrades: Why is upgrading towers mid-battle so essential? Wouldnt it make sense to offer several different flavours of each tower?
one-sided: The turrets never take any damage from the creeps. Why?

I'm breaking all three of them, so hopefully I'm not setting myself up for a fall there :D

[chequers]

Changing strategy mid-game should be possible. Multiple radically different strategies can succeed.

[Telefrog]

Creep pathing must either be explicitly shown or easily observable before the wave starts. I've played a couple of these games in which the direction the creeps were going to move was a total mystery. Not fun.

Towers need to have upgrades and options. Also, any penalties for changing your mind on placing a tower shouldn't be too punishing.

I don't mind the first person or over the shoulder view that some games use, but I do think that games that use those views need the pauses between rounds. It's too easy to miss which towers need repair or which way the next creeps wave will attack from when I'm stuck in FPS view.

[Ben Sones]

I actually love controlling one dude in the middle. It adds an extra element to the mix, so success is dependent on both maintaining good defenses and helping to fight back the attacks. I inevitably get bored with games that are just about placing defenses. Maybe that's just me, though.

[Marcin]

I never got into TD - too puzzley, and the time investment required only to fail at the very end because of something I can't counter is not something I can spare. Or at least that was my view from the handful I tried before giving up on the genre.

The "dude in the middle" concept actually got me interested again, because it feels much more active, much more directly involved in the defense. OMD is ideal because the mage really *can* make a difference, but if you don't upkeep your traps as well then you'll fail. Dungeon Defenders is much more classic to me in that any single person will not succeed for long and you *must* rely on traps to win (in fact I believe there's a mode toggle for this to switch entirely to noncombatant, just constructor), and for that I need coop. I just don't find the puzzle aspect that entertaining.

[WarrenM]

I hate that. I don't want a dude that I control. I want a god's eye view of the battle field as I deal with units and placements and upgrades.

[cliffski]

Towers need to have upgrades and options.

But do they need mid-battle upgrades?

If you have the option of gun tower I, gun tower II and gun tower III, is it really an essential requirement for gameplay that you upgrade a I to a II in mid battle?

I know that's in all TD games, but I wonder if it is really needed. If you have the cash you can plonk down a I and then click upgrade, upgrade, so why not offer all three from the start?

[Jab]

One thing about upgrades that I didn't like, which I saw in revenge of the titans, is being able to choose an unlock after every mission from a pool of upgrades. The reason is that first time players will never know which ones to get first and usually leads to screwing themselves up by not having the right towers unlocked.

With multiplayer, I like it as well, the only problem with the convention is when you have multiple paths like in the old Warcraft 3 mods, where a crappy partner becomes a liability when you clear your entire wave, but lose because your friend completely failed their wave.

[jason]

I'm in agreement with Ben. I love playing League of Legends and would really enjoy a game that let me place/upgrade towers, be attacked from multiple directions, and use my dude in the middle to recover from failures in my tower placement.

[Shellfishguy]

Defense Grid is a great example as noted above, but I think Dungeon Defenders does do a number of things right. Towers and defenses can and will be destroyed, which since you're also in the game fighting, makes you juggle the need to repair/upgrade towers or go about killing creeps yourself.

One thing I think has become essential is some sort of display showing what kind of creeps are coming up in the next wave. Sanctum gives you pictures of which creeps are next but not numbers while Dungeon Defenders gives you the exact number and composition of whats coming through each door.

A good co-op mode would be awesome also.

[WarrenM]

But do they need mid-battle upgrades?

If you have the option of gun tower I, gun tower II and gun tower III, is it really an essential requirement for gameplay that you upgrade a I to a II in mid battle?

I know that's in all TD games, but I wonder if it is really needed. If you have the cash you can plonk down a I and then click upgrade, upgrade, so why not offer all three from the start?
Well, there's the timing aspect. That takes longer that simply dropping down a level 3 tower.

But, really, what's the difference here between what you're describing and an upgrade system? Are you saying players need to sell off the existing tower in order to build a new one, as opposed to clicking "Upgrade"? That doesn't sound like enough of a difference to matter, really.

[Pogue Mahone]

Still, I kind of like the idea of having the option to leapfrog over the I and II prereqs and just throwing down a level III rocket launcher if you needed to. Maybe have them cost slightly more resources than a straight I->II->III upgrade? But having the option would be a nice to have.

[Shellfishguy]

And if you don't have an in game avatar and aren't upgrading towers, what ARE you doing in the combat phases? Just placing towers? Unless the pace is really quick, I think a player would need some other interesting decisions to make.

[WarrenM]

And if you don't have an in game avatar and aren't upgrading towers, what ARE you doing in the combat phases? Just placing towers? Unless the pace is really quick, I think a player would need some other interesting decisions to make.
Part of the appeal is setting up your defenses and then seeing how they fare. Traditional tower defense games don't have a constant source of stimulus for the player's fingers.

[Pogue Mahone]

I guess the answer to your question, Shellfishguy, depends on what you're looking for in a tower defense game. For myself, I enjoy the puzzle aspect, trying to set up the perfect kill zone and then releasing the encroaching enemy to hopefully die within. I guess it's like those people who set up dominos or houses of cards - the fun and the challenge is the setup, with the final result (the push) being the payoff.

[MarchHare]

There MUST be a meaningful strategic decision between upgrading an existing tower or building a new tower of the same type. In some games, it's always better to do one or the other; the best TD games are ones where both strategies are viable depending on the situation.

All towers must be unique and useful. Don't force me play a few levels with crap towers that I'll never use again once I unlock the "good" ones. Even the lowliest starter tower should be valuable in the right situation.

Don't make me build specialist anti-air towers that are essential 10% of the time but otherwise completely useless.

Towers that interact with each other to form combo attacks are cool. For an obvious example, you could have one tower that shoots oily tar on the path to slow the creeps and then a flame tower that ignites the tar for bonus damage.

I know this one will be contentious, but I greatly prefer TD games where the creep path is set in advance and can't be adjusted by the player. I don't enjoy having to build my own maze of towers. As slantz noted above, this often devolves into a gimmicky strategy where you juggle the creeps' movement which just feels cheap.

[cliffski]

well the current design of what I'm working on has you design the towers yourself from components, so you can have a whole huge list of different gun towers, some with longer range, some with higher splash damage etc...
The flipside of that is that you cannot (currently) upgrade any towers already placed. I am toying with the idea of being able to repair towers (they take damage).

[guppy]

This may be obvious, but I hate almost every tower defense game because they frequently do sweet fuckall to distinguish themselves. If your game doesn't have something unique to offer, I'm not likely to be interested.

I dislike it when I don't have enough resources to do much of anything in the beginning. While I love Dungeon Defenders, I am annoyed about the fact that I can only build maybe one trap per person in the first round. Yes, I can probably kill everything myself if I have to, but the whole point is the towers/traps.

[Foxstab]

What absolute must-haves there are in a tower defense game for you to enjoy a title in the genre

What things do TD games do that irritate you?


I'd say absolute must-haves will be mini-bosses and bosses.
The boss fights in themselves must be really challenging. The mini-bosses function like a massive hulk battering ram or what have you that unless you stop, and it's damn hard to stop, it's going to not only breach your wall, it's going to get inside your base, rampage and systematically destroy everything to the point that recovery and pushing it back is unfeasible and defeat is inevitable.
Id est you have limited time, as an emergent mechanic, of how long that thing is 'permitted' to live. You can suffer some damage from it, but unless you dispatch of it then it's going to ruin it all, everything you've labored to date. Game Over.
Also, some bosses/mini-bosses must have resistances so they're only vulnerable to certain weapon type and possibly bosses become a 'puzzle fight'-esque whereas you must perform certain actions to bring it down or take it apart in several stages, one piece at a time.
These things are the threats that whenever they show up on the screen put you on the edge of your seat and force you to focus and put all your energy onto bringing them down.
All the while managing defense for the rest of your perimeter, otherwise all the little moblings that assist the boss are going to overrun you if you neglect to pay them any attention, once you've managed to finally drop the boss.
Also: fodder. It's a Diablo principle. Between strong monsters you go through fodder. Makes you feel good about yourself and strong.


And what they do to irate me is boring repeat. When the map doesn't change, the enemies are just essentially same thing over and over again.
Also: unfair situations. When the only times the game put you in danger of defeat is essentially not by testing your skill, but because the random generator of mobs decided to just throw on you 20 bosses at once alongside 100 fodder that just overwhelm you because there's no way you could oppose those with the best FPS/RTS/what-have-you skillful person alive.
Instead of putting you in danger because you slipped up, overlooked, were negligent or simply not good enough, or the AI out-smarted you (even small things, like hiding a potentially destructive unit like battering rams/sappers amongst a horde of dump-infantry) to gain a foothold.
When you're being beset, especially due to your own mistakes, it's suck to lose but you know WHY you lost, or you know it's YOUR FAULT. So you can live with it.
When the game outright blatantly cheats you, it's infuriating.


If money and time was no object, what would the ultimate tower defense game have?
Scope. Unparalleled scope. We're talking about taking a bite, a chunk, off of a RTS game, and limiting it to base-defense design. But all the while you have this rather gigantic base of considerable land acre-age that requires constant defense with limited, slowly generating, resources and tactical decisions must be made as to what to produce, when and where. As well as defensive forces deployment.
Also, zombie-survival-esque nightly excursions outside base camp onto enemy-ridden territories in order to salvage extra materials, champion units, technology which upgrade your plasma turrets +0.01 fire rate, or otherwise assets/objectives which promote and assist the defensive effort.
So for all purposes the game functions like a RTS, except there's no "kill all enemies/their base" win condition. It's purely about survival of your own base.
You get rated or whatever according to your performance each # days/# waves/# hours/whatever interval you consider to be meaningful for a 'phase' or 'level' to designate an intermission between sessions. How many troops survived, how many structures survived or vice-versa were killed/destroyed.
If there are resources rewards granted then they also match the rating. And of course, all sorts of 'chivos that grant you extra credit.


For me, TD is about nervousness. Concern that the forces that you have are not going to quite hold out aginst the forces coming your way. It's a game based on uncertainty and the battle being a 'damn close run thing'. Plus the slight panic of making decisions against the clock. (I rarely pause TD games). Am I in the majority there? Or do people treat them as very clinical puzzle games?
I'd say amongst designers you're in majority.
I'm uncertain amongst players, there seem to be a divide in there. Mostly due to players' own personal tastes (and also, the over-achievers/hardcores/min-maxers who over-analyze the game rather than simply play it due to seeking optimal/nigh-perfect results).


Edit: In respect to controlling a unit....well, in a FPS-style TD whereas you have menus to manipulate assisting forces/assets and you can single-handedly with great skill upset the balance and turn the tide I suppose I can see the appeal. You're both acting commander AND you get to SHOOT SOME SCUM BACK OFF YOUR BACKYARD. It'll require a rather simple-yet-powerful assets commanding system as well as a comprehensive radar and large-map/satellite-uplink in order to get a good view of the entire field at once as to have updated intel on how the fighting goes.

Personally, I don't mind having a representative RPG-esque avatar that you can control, even with WASD+left-click/ctrl (preferable, actually) rather than just give automatic RTS mouse commands. And then level up and power up and it becomes a useful tactical asset that you can employ and it becomes strategic decision when and where to use it (could also make it high-resource consuming of sorts, as to render even its mere use expensive, thus, strategical) but highly effective and can contain a situation from rapidly becoming a sure-defeat.

[Pogue Mahone]

But I think there could be strategy in having the option of choosing a lower power tower (ha!) or a fully upgraded one from the start -- they're useful for different things. If you want to funnel enemies along a path, you may want more and weaker towers to create a path. But to protect a certain area, you may want fewer and stronger towers to just murder stuff. I can't see a downside here.

[kerzain]

In PvZ I like that there is more to do than simply plopping down defenses. I like that part of the game requires players to actively seek out and hunt for the bonus suns & coins (used as currency during play) that would pop up, and fall throughout the level. In Defense Grid I often feel like I'm just sitting around waiting for money to accumulate. Aalthough I can speed the game up, that's sort of cheating the player out of actually playing. I'd rather spend the keystrokes I spend speeding past all the dull parts, and instead have something fun and interesting to do. Sometimes in Defense Grid I just feel like I'm not so much playing the game as watching the game. In PvZ, except for the early/easy/training levels (which admittedly last way, way too long for a gamer like me, but worked well for a gamer like my wife) I never got this feeling with PvZ (once the game picked up), and it seemed much more engaging to me.

Variety of defenses is also key to my enjoyment. I really don't care if there are ten different defenses available if they're all basically damage turrets with varying rates and spread of fire. If there's only a halfhearted effort made to include some sort of useless debuff/barrier that would best be replaced with yet another weapon, I'll never use the barrier/debuffer. To me the best TD games make slowing down/debuffing/alternatively affecting the enemy units just as important, and fun, as blowing them all to hell.

Variety of enemy units, very very important. I don't want a dozen units charging at me, with the only difference being how fast they move. Look at PvZ for a good idea of how to incorporate variety. They have so much going on in that dept, they're the masters (so far as I've experienced).

I like the idea of having different games modes available to help earn currency used to unlock upgrades (which can then be used in the main game). Sure, we could earn currency in the normal game too, but it's much more exciting to play different game modes, which can still be fun, even if not as fleshed out as the primary mode. It keeps the game feeling fresh, without simply tacking more and more generic levels at the end of the campaign.

I know some folks don't like the idea of controlling a specific unit in these games, but if the game is like Trenched & Orcs Must or Demigod & DOTA, where the players are in control of an avatar of some sort and gets to annihilate units at will -- then I don't mind at all. In fact I prefer them. They're much more engaging than a simple game like Defense Grid, where you're just sitting there plopping down tiles all freaking game. What I like about the games that have players in control of an avatar is that it gives us so much more to do than buying and deploying, buying deploying, fast forwarding past the dull moments, buying and deploying. Action, baby. Keep us busy doing stuff, not just sitting there watching things happen. I don't want to spend more than 75% of the game clicking on upgrade buttons and deployables. Even though players are not in control of a unit in PvZ, it managed to keep players busy doing other minor things (collecting)besides plopping down defenses and watching zombies get plastered, especially in mini-games. I guess my preference boils down to liking a lot of DOTA & FPS in my TD games.

Multiplayer is give or take depending on the type of TD game we're talking about. I wouldn't want to play a multiplayer PvZ game, but Orcs Must Die is stupidly handicapped without it.

[Ben Sones]

I guess the answer to your question, Shellfishguy, depends on what you're looking for in a tower defense game. For myself, I enjoy the puzzle aspect, trying to set up the perfect kill zone and then releasing the encroaching enemy to hopefully die within. I guess it's like those people who set up dominos or houses of cards - the fun and the challenge is the setup, with the final result (the push) being the payoff.

Right. That's the sort of tower defense game that I don't care for, personally, but it's a valid approach that plenty of people enjoy. I think it's worthwhile to break the genre into two categories--the passive-TD games where you set up a defense and then see how it fares (i.e. "traditional" tower defense), with most of the player input happening before the battle begins, and the action-TD games where everything happens at once, and where the player takes some sort of role in the defense. That can include controlling a dude on the battlefield, as in Dungeon Defenders, or it can be a more god's-eye view building game like traditional twoer defense, but one in which all the building happens while your defenses are under assault (eg. Plants vs. Zombies).

I think it's a good idea to start by getting a handle on which end of this spectrum you are aiming for, cliffski. That will help to inform the more specific design choices.

[Shellfishguy]

well the current design of what I'm working on has you design the towers yourself from components, so you can have a whole huge list of different gun towers, some with longer range, some with higher splash damage etc...
The flipside of that is that you cannot (currently) upgrade any towers already placed. I am toying with the idea of being able to repair towers (they take damage).

I have to say I really like the sound of this. Being able to tinker with the parts and coming up with different set ups for different needs really hits the spot with me. I think I could deal with a more static combat phase if each tower was a custom creation of my own. Tinker away - Fight - Tinker to adjust - fight etc etc. It gives the player meaningful control and decisions over the field.

[Mr.GRIM]

Tower upgrading is a must, be it new toys or existing tower strength. I prefer a system that does not make large chunks of your arsenal obselete however, because that just ends up really limiting the defenses I want to put out there.

I really love being able to actively manage my defenses during the wave, be it upgrading,placing new,upkeep or whatever. Give me something to do other then stare at the screen.

Satisfying killing. Sounds basic, but I have played too many TD games that lack in this area. I want my defenses to have impact both visually and acoustically. I love seeing the result of my defense in the forms of corpse mountains or twitching scrap metal. This is also aided by

Tower Synergy. These games really shine for me when multiple tower effects become greater as a whole than the individual towers. Depth here is key. It gets me really thinking tactically about the what/where when placing defenses, and watching your well thought out deathtrap in action is sweet.

Finally, and most importantly - Cool maps! I am admittedly a map whore, but If the battlefield that the majority(if not all) is not interesting, then I am not interested in playing the game. Terrain variety, shortcuts/multiple paths, little details and context all help with this.

[MarchHare]

Something else I'd like to see: the ability to customize the targeting AI of individual towers. For example, imagine a game that has a high refire rate/low damage machine gun tower and a high damage/slow firing cannon tower. Allow me to set the behaviour of my towers so that when there's a choice of multiple different targets, the MG favours zergling-like swarm creeps and the cannon favours the heavier enemies.

[inkai]

Anyone played the Wc3 TD map where, 7 players had to build the towers and one player summoned the waves. He'd get money by destroying towers and regular income with the spawns.

Kind of like the TD where you had to spawn to get money but more refined.

[Pogue Mahone]

That's interesting inkai, I haven't played that. But I like the idea of head-to-head tower defense, are there any other games that offer this kind of experience?

[WarrenM]

Also important is graphical clarity. Some TD games go for a realistic look to everything and I find that once you zoom the camera back, everything turns to mud and you have a hard time picking out your units.

Defense Grid did a good job of this, actually. Good graphics but also very clear.

[caesarbear]

I don't play that many TD games, but I generally like the ones that give you lots of options and let you adjust on the fly. Not being able to adjust during battle seems to assume that the player already knows everything about the game or has the patience for all the trial and error required to learn everything. The battles in GSB were pretty to watch for a while but soon you just didn't care and wanted it over as quickly as possible so that you can get back to the actual gameplay. I prefer the TD genre when it's closest to it's RTS roots where you start with few resources and build from there, in the midst of battle.

[Dean]

I would like some sort of save system so if I screw up on wave 99 (and I understand you're getting rid of waves, but say, late game) that I don't have to start over from scratch. Usually going back 2-3 waves and making some different tower choices would allow me to get through the killer wave.

It seems stuck in old arcade land in terms of a save system.

[Hugin]

There are a lot of conventions that exist in TD that people never try to play with or break. For example:
waves:
upgrades: Why is upgrading towers mid-battle so essential?

Upgrading towers mid-battle forces the player to decide if they're willing to shut down an area to make it stronger (in almost every case I can think of, upgrading a tower de-activates it during the upgrade, and frequently higher level upgrades take longer times), and if they want to do this near the beginning or the end of the map (usually putting firepower near the beginning of the map is better, but often you need to upgrade on an emergency basis to catch creeps that aren't going to die in time, near the end of the map. Making yourself temporarily vulnerable, and choosing when it's safe or acceptable to do so, and deciding between "optimum" tower strength improvement and "emergency" improvement at a nice tactical layer, and they add tension.



Wouldnt it make sense to offer several different flavours of each tower?

In general, no single tower should bifurcate into more than two or three different types of tower (it can have many levels of power so long as the fundamental nature of the tower doesn't change too much). More than that (and there are a few TD games that do this) and the interface becomes a mess, keeping mental track of which towers do what, how upgraded they are or can be or aren't, and whatnot becomes a pain, and exploring the consequences of changing towers becomes very difficult as well. You can have a bunch of different types of tower, but in general, strongly "themed" towers that are easy for the player to identify and remember are best.



one-sided: The turrets never take any damage from the creeps. Why?

This is not unheard of at all. I can think of several TD games where towers take damage. In general, it's an annoying money sink. Theoretically there's tactical value in making the player run around repairing towers and being threatened by their loss, but I feel in almost every case I've seen it's more punitive than fun. TD in generally about carefully making an interesting puzzle-like defensive solution to the creep problem (with occasional stabs of brute-forciness, as someone said earlier, it's important that the player occasionally be rewarded with periods of dominance where creeps get utterly vaporized for a bit). Having the answer be "oh, the creeps just destroy your shit" is annoying.

[kerzain]

Oh, I want to emphasize something I strongly encourage: A monster & defensive structure/unit encyclopedia. I enjoy reading info about this stuff without being forced to sneak glimpses in during gameplay. Having it built into the game is so much better than waiting for a fan site or wiki to possibly put the info up sometime down the road.

[cliffski]

Finally, and most importantly - Cool maps! I am admittedly a map whore, but If the battlefield that the majority(if not all) is not interesting, then I am not interested in playing the game. Terrain variety, shortcuts/multiple paths, little details and context all help with this.

I am surprised there isn't more of this. My game has a built in map editor aimed at the average gamer, so there should end up being infinite maps. I think thats something really lacking from most TD games.
(There will be integrated map-sharing, like GSB shared challenges)

A lot of the maps will obviously suck, but I'm hoping some will really hit the spot, and user-ratings of maps should make the good ones easy to find.
In theory :D

[peacedog]

I know that's in all TD games, but I wonder if it is really needed. If you have the cash you can plonk down a I and then click upgrade, upgrade, so why not offer all three from the start?

The devil is in the details. If I have to sell the existing tower to replace it with a better one, that's really just some needless UI tedium. Is this the type of battle where I'll be facing a lot of waves? Or am I more concerned with initial setup and hoping it all works out/with less in-battle change/upgrade/etc? I prever to kick to upgrade over having to constantly sell/pave over/etc an existing tower.

The upgrade mechanic works really well. It works especially well when there are clear costs/benefits associated with it. Desktop Tower Defense nailed this; the last upgrade is much, much more expensive (and the previous upgrades scale up in cost/effect too) but you get so much out of it. A lot of TD games just have 3 or 4 upgrades and progression is mostly linear and mostly boring.

[instant0]

I want it to have COOP mode if it is "new style" TD, in that you also control a player that can run around and fight/build stuff. If it is old style, it can stay Singleplayer.

If it lacks maps/modes it will need lots of challenges and "mutators" to keep the low number of levels interesting in the long run.

On the other hand, if it has lots of maps/modes, challenges and mutators would be fun nevertheless.

[Hugin]

I am surprised there isn't more of this. My game has a built in map editor aimed at the average gamer, so there should end up being infinite maps. I think thats something really lacking from most TD games.
(There will be integrated map-sharing, like GSB shared challenges)

A lot of the maps will obviously suck, but I'm hoping some will really hit the spot, and user-ratings of maps should make the good ones easy to find.
In theory :D

cliffski, most TD games don't have map editors because most TD games either allow you to make your own maze design to begin with, or the maze design is very carefully the key to the challenge of the map i.e. tower placement is really critical, and user made maps would probably mess that up.

[JoshV]

I've always wondered why upgrading wasn't a bit more branching. Toy Soldiers messes with it a little bit, since it seems like on the surface from the descriptions it might not always be best to upgrade, as you trade things like fire rate for damage, but in practice it's always best to do so. Interesting TD games have choices that matter, upgrading over putting another tower down. Which tower type to use, how best to place your towers, etc.

But for Cliffski's design, which seems to be less about slowly building up after wave and wave, upgrading would be unneccesary. That's more if you want to start with a puzzle/defense design and slowly grow it to accomadate larger and more diverse waves.

Btw, the reason there is a wave mechanic and not just an endless horde is so that the player has room to breathe and relax and to give it a form of pacing. It would be like a horror game that constantly has stuff attacking you, instead of building the tension. I suppose you could do that with constant attackers, but then only spawning in strong waves occasionally. But then the constant attackers would need to be fairly weak and pathetic, so why spawn them at all?

Though I agree that many TD games could use a shorter ramp up time, in a 30 wave game, I often felt like they could've started at wave 10 or so.

[Hugin]

I've always wondered why upgrading wasn't a bit more branching. Toy Soldiers messes with it a little bit, since it seems like on the surface from the descriptions it might not always be best to upgrade, as you trade things like fire rate for damage, but in practice it's always best to do so. Interesting TD games have choices that matter, upgrading over putting another tower down. Which tower type to use, how best to place your towers, etc.

But for Cliffski's design, which seems to be less about slowly building up after wave and wave, upgrading would be unneccesary. That's more if you want to start with a puzzle/defense design and slowly grow it to accomadate larger and more diverse waves.

Btw, the reason there is a wave mechanic and not just an endless horde is so that the player has room to breathe and relax and to give it a form of pacing. It would be like a horror game that constantly has stuff attacking you, instead of building the tension. I suppose you could do that with constant attackers, but then only spawning in strong waves occasionally. But then the constant attackers would need to be fairly weak and pathetic, so why spawn them at all?

Though I agree that many TD games could use a shorter ramp up time, in a 30 wave game, I often felt like they could've started at wave 10 or so.

Most decent TD games have a way to jump start waves if you're just sitting around, but "kickstart" modes with extra money and a harder/bigger start are nice as well.

[peacedog]

I've always wondered why upgrading wasn't a bit more branching.

The Protector games have a ton of branching in the upgrades (the mechanics vary somewhat from version to version but build on the same theme).

[instant0]

In addition to the earlier comments regarding COOP.

How about an adversary mode, where one player (or several) will build the defences, whereas another player (or several) will decide which units will attack, which entrance they will use, even select their path and possibly also being boots on the ground.

Even the single player game could do that, let you switch between clearing the 'campain' as attacker, or as defender.

[cliffski]

This is all very excellent debate. The point about the sunflower mechanic on PvZ is well made, in terms of giving you stuff to do between building towers. I have a nice idea for a similar mechanic for my game

One thing not mentioned is the predictability of the enemy attack. You know the order and type of creep after you play a level 5 or 10 times.
My game has AI controlling creep selection and placement so it is different each time, and hopefully adapts slightly to your defense layout.

In a way, this is TD heresy, but I'm trying to make something different rather than classic TD. I still think this can work. Am I mad? (I have a system in the online challenges that has predictable AI, like the normal method, as well)

On the topic of player-made maps probably sucking, this may be true, but in a community of a decent size, there will be some decent map makers. The team making the campaign maps is *me*, so even if 1 in a thousand players can make maps as good as the developer, its still a vast ramping up of potential quality maps no?

[kerzain]

As long as there is a rating system in place, there could be any number of crappy maps submitted, but the cream will rise to the top.

[mostlytigerproof]

Cliffski has a great point about the way the genre requires the exact perfect difficulty in order to have any tension at all. I've noticed the tower defenses that I like have a lot of ways that the player can manipulate the difficulty level. Take Gemcraft Labyrinth:

You can apply optional difficulty modifiers at the start of a match. They give you XP rewards.
You can rush waves. There's a cash reward.
You can spend resources on waves to intensify them. XP reward.
Some levels have sealed tombs, filled with demons. If you apply enough damage to the tomb, all the demons spill out and you get an XP bonus. They're completely optional.

The player antes up in a variety of ways before or mid-way through the level, but once they commit to a difficulty bump, there's no going back unless they restart the level. It might not interact well with a save/undo mechanism.

[mostlytigerproof]

One thing that really bugs me about Tower Defense games is that the fiction on top of the game mechanics seems totally wrong. A bunch of meelee dudes running single file past ranged opponents doesn't evoke combat at all.

I always get a production line vibe from Tower Defense games.

[cliffski]

A bunch of meelee dudes running single file past ranged opponents doesn't evoke combat at all.


Except in world war 1, where a bunch of people regularly charged emplaced machineguns with nothing more than rifles and bayonets.
Hence my game is *sort of* set in a WW1 environment* :D

*but with lasers and mechs

[slantz]

Cliffski, have you played GemCraft yet? If not, go do that. It's all about configurable towers. Specifically, towers by themselves only exist to hold gems -- the quality and color of the gem it holds dictates its behavior. You can put in pure-colored gems, or mix colors for higher-level gems to get whatever balance of effects you want.

Personally I think it's a lackluster game (other than the meta-game upgrades, which I like), but it's worth mentioning because it sounds like it might have some similar ideas to what you building. Game research Homework is always good. =)

Also, re: upgrading within waves -- I like that I can generally upgrade towers within waves. Is it essential? No. But I generally pick out what upgrade/tower I want next, and I generally watch my income and buy what I want as soon as I have enough money. I find that keeps me more engaged moment to moment.

If you don't offer that, I encourage you to figure out some other method of meaningful user interaction. PvZ had sun collection and plant building during waves, for example. If you turn waves purely into a spectator sport, I'm afraid you're robbing yourself and your players of deeper engagement with the game as it plays out.

If I just want to spectate something, I'll go watch a movie, as that's probably more interesting than watching some towers shoot some baddies.

[mostlytigerproof]

Except in world war 1, where a bunch of people regularly charged emplaced machineguns with nothing more than rifles and bayonets.
Hence my game is *sort of* set in a WW1 environment* :D

*but with lasers and mechs

Even then, that's a coordinated charge, rather than a steady flow. I can't see a way around that gameplay conceit though.

[JoshV]

One thing not mentioned is the predictability of the enemy attack. You know the order and type of creep after you play a level 5 or 10 times.
My game has AI controlling creep selection and placement so it is different each time, and hopefully adapts slightly to your defense layout.

In a way, this is TD heresy, but I'm trying to make something different rather than classic TD. I still think this can work. Am I mad? (I have a system in the online challenges that has predictable AI, like the normal method, as well)


I think that can work out just fine, as long as the AI isn't allowed to rapidly change their creep makeup per wave. It would feel like cheating if I destroy the ground wave and then the AI immediately counters with all air waves. Give me time to adapt to the AI adapting to me =)

[slantz]

I love the idea of the AI and I being in an active struggle of adapting to one another.

Frankly, I find the whole trial-and-error/memorization component of tower defense to be one of the worst universal traits of the genre, so kudos to you for trying something different to get rid of that.

[cliffski]

Thanks for all the tips, I'll give gemcraft a try

[Tman]

In order of priority, TD games must have:

1. Repeat ability: If I lay down the same towers in the same way, I must get the same result. Eg, randomness sucks. This means predictable pathing for the creeps, it means the towers must fire at the same targets each time I do this.

2. Block placement should be crystal clear and unambiguous. Some like Defense grid, use a grid so it is clear. Orcs Must die fails a lot with me on this because while it shows an outline, it is not clear if it is adjacent to another block. This is mostly due to the oblique angle as I'm in a FPS mode, close to the ground, but could be solved by lighting up adjacent objects somehow. The worst thing in the world is to misplace a tower.

3. Pathing rules must be very explicit and clear. I love Orcs must die because it shows me the direction of the paths and as I change the layout. Desktop tower defense had a creep that would explode into multiple creeps and made it very clear they could squeeze between two diagonal placed blocks. Their subsequent creep that hopped over walls made me so mad I quit playing DTD even though I could exclude it.

4. Show me wave composition before the wave begins and ultimately show me the wave composition as it's going on. This is something that Defense Grid does so well. I don't need to know specifics, but in general. The reasoning is that because of #1, I could write down each wave, but why should I have to do that? the game should do it for me.

5. Zoom in / out is a must - and why limit me on my ability to zoom out? This always bugged me with Defense Grid. Why stop my zooming out and force me to pan?

6. Time is a necessary component, both for scoring and for manipulation. DTD is probably the poster child. I can speed up the waves, and I can choose to send the next wave whenever I am ready - and getting a nice bonus for doing so. Fast Forwarding should be included.

7. Towers should always be useful for several but not all creeps. Single use towers are for the birds. And FFS, if you include air, many of the towers should be useful against both air and ground.

8. Towers must be upgrade-able (see below for some alternate ideas). The fact is creeps should get tougher & tougher and I shouldn't be forced to solely lay down new towers.

9. Thou shalt include an endless mode or a +100 wave mode, no matter what. It is optional, but you must have this.

10. You should be able to move back in time. Defense Grid got this the best - each press of the backspace key takes me back a certain amount of time. I don't need a save, but I need to be able to go back in time to fix a major design function of my maze if a creep or creeps slip through. However, I would suggest recording this so when you have a certain score, it has an *4 to denote you used the backspace key 4 times.

11. Statistics. Tons of stats. Towers should be very clear. Range, ROF, DP, Type and whether it has an AOE component. Ditto on Creeps. I should be able to easily see how any tower or creep either can deal or can be dealt and how much is left.

12. Coop / multi-player component. At a minimum, the ability to share & compare. I'm not a huge fan of coop. My OCD complex has be wanting to perfect a map, so I enjoy doing it again & again until I'm satisfied.

If you're going to break the mold, I would suggest a few things that could really set it apart. As kerzain says, keeping busy is very important. Why not include a resource component as well as a tower component? For example, If I have lasers and can hook them up to a power grid, the strength of the laser is determined by how much power I can feed into it. This could also have a defensive property such as shields - so I can either build a new tower, or I can build more power generators.

MarchHare said it best when he suggested customized targeting. This is why the FPS is flourishing -> People get tired of towers that are built for a big punch wasting their shots on a small target. If I could define rules for my towers - here is my top 10 targets, in priority order, for example, that would be awesome.

[JoshV]

eh, I think target priority doesn't really need to be customized by the user. Air stuff should shoot air, rapid fire weak damage stuff should shoot fast/weak stuff, slow high damage stuff should shoot armored/high hp stuff first. Is there ever a case where those priorities should change? Are you ever going to want your super slow firing high powered shooting thingie to shoot at weak stuff over high HP stuff if both are in range?

It gets a little fuzzy if you throw in variables like distance to the goal and how clustered targets are (for AoE stuff) combined with fire rate, but at that point, the amount of work the user would have to do to fiddle with all those variables is getting a bit much. Might as well just toss a manual fire button, or a hold fire/fire toggle, or select the tower and click to set its target.

EDIT: but the danger there is that if the game requires that kind of extra micro, it could be overwhelming for some players.

[Spasticon]

I am a real TD aficionado. I'd agree with most of the comments here that Defense Grid is probably the best out there, although I also got a real kick out of toy soldiers on xbox live. In both of those the maps were fixed.

There's something missing from the discussion so far though, and that is the minecraft style appeal to the open maps like in desktop tower defense or fieldrunners... that is that I get to design the map myself each time I play it during the playthrough. Granted, if mid-wave tower destruction is possible then you end up with stupid pathing tricks, but that could be easily overcome with a build time on the towers.

Thought on FPS: I played Sanctum on steam quite a bit and... it was interesting and fun, but after a while it got really frustrating when my towers sucked much more than they should have and I had to do most of the heavy killing myself. Toy soldiers handles this much better, with the ability to take control of any cannons if you want to (more for fun than anything), but if you leave them alone they kick ass too, but it's not a true FPS. I liked Sanctum FPS only in that it felt a little like minecraft.

A true 100% minecraft style FPS approach would be interesting... where the mobs actually move up and over terrain which the player can build... but I think that's moving the discussion in a different direction.

Also... mid-wave tower upgrades: It's only a compelling mechanic if there is a drawback where the tower is offline for a period of time.

[Dawn Falcon]

The TD game I found most fun is, to this day, Ghost Hacker.

[Teiman]

I am Tei, and my favorite TD game is Vector TD (http://www.candystand.com/play/vector-td).

I also like (in no particular order) Dungeons Defenders, Defense Grid, Harvest: Massive Encounter, geoSwarm, Orcs Must Die, Sentinel 3, PvZ and others.



- What absolute must-haves there are in a tower defense game for you to enjoy a title in the genre


"Good graphics". But good graphics here means that I can sit, and see my towers gloriously destroying to bits the enemy. It feel goods to see my strategy working, to feel that, with nice graphics. Take note that nice graphics is hard to define, Vector TD have great graphics and most are just lines and triangles.

A puzzle-ish as the core of the game. I like to play Turret Defense games withouth a computer, with the eyes closed, on the bed, or maybe taking a sower. Thinking about how to beat a level or a problem. Puzzle is maybe the wrong word, because most puzzles have only one solution, and I probably want to be creative and invent my own way to solve a problem. I thing Gratuitous Space Battles is in this category.

Let me think!, this is my taste, I like TD's that let me think. Some TD games don't let me build with pause mode, or everything rolls automatically, and I have to manage. Some people like that, others don't. Different people like different things in TD games.



- What things do TD games do that irritate you?


I don't like to get a RSI and break my logitech mouse to beat a turret defense games. I know some people like to control a tiny ship in the battlefield (the commander) and make reaction speed part of the formula. But I just don't like that, and wen I need to click, click, click, click.. so the faster I click, the more DPS, I hate that. But I am being ilogical, because Dungeon Defenders as a lot of that, and I still enjoy it.

Getting stuck in a level forever. So much that the game feel "unfair" and imposible to solve.

Boring TD's that don't try to innovate in some way. Defense Grid was very clasical, but the good production values, and some mix of TD elements turned it into a excellent game. But I would not play a game that is clasical and with poor production values.

[Alan Au]

Okay, I'm going to throw a bunch of ideas into a big pot and stir it around, based on experience with Defense Grid, Plants vs. Zombies, random quirky Flash-based tower defense games (e.g. Warfare 1944), etc. Throw in some squad-tactical stuff for good measure, something along the lines of Space Hulk where you can have units control an area or an approach angle.

I think it's important for the player to have some sense of control, which means predictable enemy paths, or chokepoints, or some way that the player can decide on a strategy before the timed-portion begins. If enemy movement is too random or too complex, you risk ending up with a skill-based action shooter rather than a strategy game. X-Com and Space Hulk had doorways and hallways you could cover.

If the player moves along the same paths as the enemy, you can have a push-pull thing going on. I suppose you could even have the player move along different paths, as long as the paths interact in some way. This is the Rescue Raiders/Armor Alley thing.

Invulnerable towers are fine--it's just one less thing to worry about, meaning the player can spend more time on other things. Player attention is a resource too. Vulnerable "towers" are also fine, although it can sometimes make an encounter seem like a battle of attrition.

I'm not a fan of "puzzle" levels where there are 1-2 "correct" ways to solve levels.

Waves are okay, as they provide a break between frantic sections.

I'm not a huge fan of player-as-avatar in these because I think it shifts the balance towards action and away from strategy, although it can work sometimes. Maybe make it a backup option that carries some score penalty, etc. Total Annihilation had the powerful commander unit, but firing his main gun used up a lot of resources, and you lost the game if he died.

[Hugin]

The TD game I found most fun is, to this day, Ghost Hacker.

Ghost Hacker is very good, and it has the most interesting tower upgrade/customization system IMO.

[Nathan Phoenix]

X-Com and Space Hulk had doorways and hallways you could cover.

Oh god, now I want X-Com and Space Hulk tower defense games!

[Shmtur]

I've always preferred the ones with multiple difficulty levels. I don't have the time or inclination to figure out the optimal setup, and I also have no desire to be forced into repeating content. Defense grid also handled this well with the rewind feature. I very much appreciated that I didn't have to start over completely because I placed things suboptimally!

[TranquilityBase]

I like the TD games that allow you to mix tower types together for combo attacks or transform into something else off their individual native upgrade paths. The Element TD mod for WC3 did this really well. Combine flamethrower towers and watercannon towers to make a steam trap, water+darkness=poison, etc. Some could be turned from offensive cannons into buff towers, or provide some other benefit. On the flash side, the Gemcraft series, Onslaught 2, and Bubble Tanks TD have some nice combo creations as well.

[Spasticon]

Oh god, now I want X-Com and Space Hulk tower defense games!

Omg yes!

[SRFisher]

waves: Why do the creeps have to attack in distinct waves? Isn't that a bit arbitrary?
Perhaps. But it does give a rhythm to the game, and lets the player alternate between being strategic and reactive.

upgrades: Why is upgrading towers mid-battle so essential? Wouldnt it make sense to offer several different flavours of each tower?Tower upgrades tend to be cheaper, and are often the only things you can afford in the middle of a battle. This is especially the case if the game is one where money is added per kill right away. And it adds strategic and tactical choice -- do you spend that 50 gold immediately to kill off the stragglers? Or do you eat the damage to your base in favour of a big specialty tower later?

Plus, don't forget two of the hidden resources of TD games: tower space and good spots (like corners). If you can never upgrade a tower, any bad choices you make during planning are that much harder to recover from. And if you can't recover from your mistakes, you're just waiting to lose.

one-sided: The turrets never take any damage from the creeps. Why?Ahem. Plants vs. Zombies?

Initially it was an innovation, a radical shift from the standard rules of RTSes. What kind of game would you get if enemies never attack? I suppose TD games are an established enough subgenre now that building damage becomes innovative again.

I'm breaking all three of them, so hopefully I'm not setting myself up for a fall there :D

[Wade42]

My favorite TD-ish games are probably Plants vs Zombies, Monday Night Combat... In general, I like games that mix manual skill with strategy, as opposed to all one or the other.

Random commentary: If you're going to make the player do math, make it be the kind of math they can do in their head. I almost rather it when they hide the numbers, a la PvZ and MNC. When creeps have 75hp, and basic towers do 14dmg, and there's 5 upgrade levels, I feel like I should be breaking out a calculator.

Or if you DO make it about the numbers, give me some tools to handle it. Let me do a 'what if' wave, sort of like Frozen Synapse (or rewind; someone said Defense Grid does this). Give me a heat map of where my towers can put out damage (or where all the creeps died). Let me respec for free if you do skill point type stuff.


eh, I think target priority doesn't really need to be customized by the user. Air stuff should shoot air, rapid fire weak damage stuff should shoot fast/weak stuff, slow high damage stuff should shoot armored/high hp stuff first. Is there ever a case where those priorities should change?
Some (http://www.kongregate.com/games/Ninjakiwi/bloons-tower-defense-4) TD (http://www.kongregate.com/games/Arkeus/glissaria) games (http://www.ninjatown.com/games/ntds/) give you 4 targeting options that you set independently for each tower (like Strongest, Weakest, First, Last). It might be useful for a few purposes (making debuffs hit multiple creeps, or setting up zones to clear out small creeps or soften big creeps), but I don't think this is a crucial feature. Smart tower AI should be able to handle that.

I don't like to get a RSI and break my logitech mouse to beat a turret defense games.
This. Also busywork in general. I like PvZ a lot, but the Xbox version is my favorite, since your cursor has a generous pickup magnet.


Getting stuck in a level forever. So much that the game feel "unfair" and imposible to solve.
Usually when I see this, it's in games with XP systems that force you to grind until you can pass a level. The same with games that give you 'medals' for passing levels; the difference between Bronze and Gold usually has nothing to do with skill/strategy and everything to do with XP level. I'm looking at you, Gemcraft*. If I *know* how to beat a level, but I have to grind to do it (well), then it's wasting my time.

* I think someone else mentioned Gemcraft... I think it's fairly well done for a flash TD game, but it's such a treadmill that I'll never go back to it.


If the player moves along the same paths as the enemy, you can have a push-pull thing going on. I suppose you could even have the player move along different paths, as long as the paths interact in some way. This is the Rescue Raiders/Armor Alley thing.
Nothing to say here, other than hurray for Rescue Raiders/Armor Alley.

[Rachel Brown]

I hate that. I don't want a dude that I control. I want a god's eye view of the battle field as I deal with units and placements and upgrades.

..but you love Orcs Must Die!

Explain!

[Kael]

Likes:

Put me down with the people that love creating their own mazes. I don't "juggle" but I can see how that would be annoying to some people, in my opinion the mechanics need to account for that. Defense Grid is the best example of this with plenty of natural obstructions you have to work around to make your maze.

Upgrading towers. I like the variation between more towers makes for a larger maze to run enemies through and bigger towers allow me to do more damage (and finding the optimal balance between them).

Differentiated enemies. I like that the units coming through my maze have different rules and behaviors. Desktop tower defense does this really well. The more creative you can get the better. The more visually distinct the different types are the better.

Dislikes:

Controlling a unit in the game.

Telling my towers where to fire their special abilities.

Special abilities I have to trigger. Though this is a minor complaint, its not to bad in Defense Grid because its only one ability. But in general I don't think it improves the game. I want to focus on my design, not action.

[Chris Nahr]

Really, just clone Defense Grid and call it a day. It's perfect!

[Spasticon]

Dislikes:

Telling my towers where to fire their special abilities.

Special abilities I have to trigger. Though this is a minor complaint, its not to bad in Defense Grid because its only one ability. But in general I don't think it improves the game. I want to focus on my design, not action.

Ugh. Agreed.

It's not so bad if they are special abilities that I, the "commander" have... But having intelligent, automated towers that are then also stupid. Argh.

[cliffski]

I just played some more defense grid to refresh my mind. I guess something that really sticks out to me now is the simplicity of tower selection. Granted, there are different abilities, and some element of matching turrets to creeps, but a gun 2 is just better in every way than a gun 1, and that is disappointing.

i much prefer the idea of different gun turrets having different strengths. Prioritising range over splash damage, or rate of fire over damage, etc, seems much more fun to me, and hopefully not just me.

Part of me does see the appeal of predictable creeps though. it would be relatively easy to have this as an optional mode... /strokes beard.

[Hugin]

i much prefer the idea of different gun turrets having different strengths. Prioritising range over splash damage, or rate of fire over damage, etc, seems much more fun to me, and hopefully not just me.

Do you mean different types of towers having different strengths and weaknesses? Or do you mean the upgraded version of any particular tower being better than the previous version?

For some TD games, tower upgrades are broken down into separate categories. So for example, you can choose to upgrade range, or damage, or firing speed as separate things. In other games, upgrades can confer unique benefits that are mutually exclusive.

In Kingdom Rush (an extremely polished game I think any TD game designer should check out, along with Ghost Hacker), you can choose to make one of the basic towers a very long range rifle tower with some high armor piercing and AOE effects, or a shorter range tower with poison and slow effects. But you can't choose both. All of the towers in the game force such choices.

[cliffski]

Thats exactly the sort of system I'm going with, because all towers are modular, and thus you are always making tradeoffs. Actually, right now you can choose 'super duper' everything for a tower, but it just makes that tower very expensive, and you won't get many of them.

[chet]

One thing not mentioned is the predictability of the enemy attack. You know the order and type of creep after you play a level 5 or 10 times.
My game has AI controlling creep selection and placement so it is different each time, and hopefully adapts slightly to your defense layout.

In a way, this is TD heresy, but I'm trying to make something different rather than classic TD. I still think this can work. Am I mad? (I have a system in the online challenges that has predictable AI, like the normal method, as well)
You remove a major level of strategy by not making them predictable. Do I spend money now or save it for later? Can I get by without buying air only defenses or do i need to buy them now?

If you remove that, you have a reactive game where the strategy becomes mushy. In a game like l4d, the adaption works because the game is about your skill of fighting and in the moment strategy.

[kerzain]

Actually, you just turn it into a puzzle game by making them predictable -- nullifying any strategy you might imagine there being.

[Robert Sharp]

I like the ones that allow you to upgrade the same tower in different ways. I think it's gemcraft that does this. Anyway, you could have a fire tower, let's say, and when you upgrade it you get different paths. It could be a wide range, low damage fire, or perhaps a focused blue flame! The second only hits one guy at a time but does more damage. The other is lower and weak against armored units but does well at hitting swarms. That kind of thing is fun to me. Upgrades are essential to the fun for me.

[Hugin]

Actually, you just turn it into a puzzle game by making them predictable -- nullifying any strategy you might imagine there being.

Obviously with TD games it's a question of balance. Some TD games are designed very "tight". Only one or a very few solutions will work at all to defeat a wave, and thus the game becomes very puzzle-y. GeoDefense being a prime example.

Others can be so loosely coded that nearly any halfway nonstupid strategy works. Or some games have a particular single strategy that happens to work on nearly every level. Frontline Defense 2 seems like a decent TD game, until you discover the missile launcher or the tesla towers alone will win all the levels.

Anyway, having set creep progressions put the focus on resource management. X gold at Y rate, to buy Z towers hoping for a level of efficiency sufficient to destroy the creep wave.

If you make the creep progression random, you're forced to code the levels "looser". There's no way to be quite as precise, because the strength and capabilities of the creep wave aren't predictable at any given time. That does reduce the strategy of the game somewhat, because the designer can't risk not allowing for a wider variety of possible solutions, which in turn means some possible levels or solutions for levels will have very easy "brute force" solutions or tower spam solutions. It doesn't break the game, it just moves a theoretical balance point in one direction vs. another.

Personally, I like a certain level of looseness in a TD game, because I get to play with different builds and still succeed. But other players will inevitably call such games too easy.

[Quaro]

Random isn't the same as not predictable.

Warcraft 3 had quite a few VS Tower defense games: each player does their setup, looks at their opponents setup, and decides what to send in the attack from a limited set of possibilities. As long as you have a good sense of the choices the AI makes you plan for a range of possible attacks.

[Tman]

Actually, you just turn it into a puzzle game by making them predictable -- nullifying any strategy you might imagine there being.

I'm not sure I agree with this. Isn't strategy a planning exercise? I can plan whether I know the wave up front or not. In the case where I don't know the wave up front, I have to at least have some boundaries - like what exactly can I expect - like chess.

The problem with most TD and randomness is that pieces (creeps) are not known that have special powers. It'd be like playing chess when you don't know the chess pieces that can be played. How exactly is that fun?

You either have a set number of pieces that will be in play for every round, or you have a number of random pieces that you tell me up front in the wave that will be spawning. Well, you can have random creeps, and not tell me, but I won't be playing that game.

[chequers]

Obviously with TD games it's a question of balance. Some TD games are designed very "tight". Only one or a very few solutions will work at all to defeat a wave, and thus the game becomes very puzzle-y. GeoDefense being a prime example.

Others can be so loosely coded that nearly any halfway nonstupid strategy works. Or some games have a particular single strategy that happens to work on nearly every level. Frontline Defense 2 seems like a decent TD game, until you discover the missile launcher or the tesla towers alone will win all the levels.

Anyway, having set creep progressions put the focus on resource management. X gold at Y rate, to buy Z towers hoping for a level of efficiency sufficient to destroy the creep wave.

If you make the creep progression random, you're forced to code the levels "looser". There's no way to be quite as precise, because the strength and capabilities of the creep wave aren't predictable at any given time. That does reduce the strategy of the game somewhat, because the designer can't risk not allowing for a wider variety of possible solutions, which in turn means some possible levels or solutions for levels will have very easy "brute force" solutions or tower spam solutions. It doesn't break the game, it just moves a theoretical balance point in one direction vs. another.

Personally, I like a certain level of looseness in a TD game, because I get to play with different builds and still succeed. But other players will inevitably call such games too easy.
post of the day

[Kael]

I just played some more defense grid to refresh my mind. I guess something that really sticks out to me now is the simplicity of tower selection. Granted, there are different abilities, and some element of matching turrets to creeps, but a gun 2 is just better in every way than a gun 1, and that is disappointing.

i much prefer the idea of different gun turrets having different strengths. Prioritising range over splash damage, or rate of fire over damage, etc, seems much more fun to me, and hopefully not just me.

Part of me does see the appeal of predictable creeps though. it would be relatively easy to have this as an optional mode... /strokes beard.

The general problem with this design is that once you find the optimal design (slowing towers right in the middle of my high damage towers, etc) each level plays out the same. You end up doing the same thing over and over.

I don't think that problem is insurmountable, but it will be a challenge in a game with wildly differentiated towers.

Defense Grid has those special towers, but in general you are right that the towers aren't as strongly differentiated as other games. In Defense Grid its more about adopting to the map you are given. Dealing with range limitations, finding the best tower for the space, finding a place to loop enemies around so your flamethrower can punish them, etc. Its about the map, not about tower combinations (in general).

I prefer that method because it makes each map a new experience for me. When I play desktop tower defense (which I also love) I generally use the same towers in the same formations even if I mix up the map design a bit. In Defense Grid there may be small points of preferences (such as my flamethrowers on C curves) but the layout varies wildly.

For what its worth my wife is a more casual gamer and she strongly prefers the Warcraft 3/Starcraft 2 mod Element Tower Defense (http://www.eletd.com/) which does feature strongly differentiated towers and no ability to place mazes. To her it seems less intimidating.

[chet]

The other issue you will run into is if you want to release a level editor - what will let this flood of maps differentiate themselves? By removing control of the creep waves the modders (and you) will lose one tool to make their maps unique.

[cliffski]

The other issue you will run into is if you want to release a level editor - what will let this flood of maps differentiate themselves? By removing control of the creep waves the modders (and you) will lose one tool to make their maps unique.

My plan is that the maps are not just maps, but maps + the layout as well, whether that is as attacker or defender.
The game records all your unit placements and times, and designs, and bundles them all up in with the scenario data itself, which you may have edited or not.

That is then uploaded like a GSB challenge.

So you can browse uploaded challenges, and download a map designed by someone else, featuring their creep designs, and their creep placement timings, and fight against that.
Or optionally, I could easily have a toggle for you to change that to just use the map, but use AI-placed (adaptive) creeps.

I'll be honest, I don't know what will work here. Maybe everyone will use the adaptvie AI, maybe everyone will prefer predictable waves, maybe people will not design maps. The only way to see what people are going to like is to try it out.

[Spasticon]

Could you have a semi predictable mid-wave creep ai upgrade? Like if the ai notices that creeps are only making it past 30% of the places towers... Then the ai announces: "a hero has emerged to lead the creeps". Heroes could be from a pool of cool random heroes or could just be stronger versions of the wave creeps.

That makes it mostly predictable, and tougher for those that are good.

[Nathan Phoenix]

One feature I like is to know the types of waves coming somewhat in advance. Like you may be fighting basic enemies now, but the next wave are the heavily armored enemies, and the wave after that will be flying enemies.

[sinnick]

Things I'm not a fan of in TD games:

- "One use" abilities, like a nuke attack or a strafing fun. Tower Defense: Lost Earth does this, and I find I almost never use them because I'm too busy focusing on tower building. Luckily I have yet to run across a level where using those abilities is required to win.

- Making the costs for towers change from one mission to the next. Geodefense does this, and I find it annoying. One level a pellet tower is $3, the next it's $5?

- Similar to above: making the power of enemies change from one mission to the next, which Geodefense does too. It essentially renders the icons meaningless, as you never really know how powerful an enemy will be from looking at it.

Things I like in TD Games:

- I'm a fan of the build-your-own-map variety, like Desktop TD. In particular, I think what DTD gets really right is its use of multiple entrances and different kinds of creeps. For example, you need to be very aware as you build your path, that on turn 10, flying creeps will show up, and unless you've developed your maze in such a way that they will go past some air towers, you're hosed.

- I don't think knowing the composition of a wave beforehand is too important. I almost never pay attention to that.

- I do think that on a particular mission, the wave order shouldn't change ... at least within one particular session. If the first wave is a bunch of light, fast creeps, then my slow, hard-hitting tower I've put up won't be at all effective. If I get killed and try again only to see a slow, tough creep come out first this time, I'd be ticked off.

- I like the gameplay of having to upgrade your towers as waves arrive is a good one.

For me, the essence of a good TD game is one of feeling unprepared. Between every wave, there should be a flurry of activity as you build defenses to prepare for it ... but you should never feel like you've done enough preparation. You should always feel like you're not quite prepared when a wave starts, so that while a wave is actually happening you're running around patching things up and keeping things going. The balance of creep strength to money you actually have is very important to get right.

[sinnick]

One feature I like is to know the types of waves coming somewhat in advance. Like you may be fighting basic enemies now, but the next wave are the heavily armored enemies, and the wave after that will be flying enemies.

See, I really don't care about that. That may be important in the first few waves, but by the time I'm on wave 10, I'm not going to start ripping down defenses to build other ones because I know a certain creep is coming. The money you get for selling a tower is so often just not worth it.

[sinnick]

Oh god, now I want X-Com and Space Hulk tower defense games!

Wow, that would be awesome. The creeps are marines, and you are an alien "growing" defenses in the walls of your ship. Beware the Dermal Sphincter!

[Houngan]

I hate "build your own map" because it's a pointless exercise. There's only a single way to build a TD map; longest possible path then juggle. Building the longest path in a square, or an X shape, or a long narrow rectangle is just a puzzle that takes five seconds to solve and fifteen minutes of drudgery to execute.

I'd much rather have a Defense Grid style with intelligent towers and maybe some UI controllable weapons.

H.

[Hugin]

I hate "build your own map" because it's a pointless exercise. There's only a single way to build a TD map; longest possible path then juggle. Building the longest path in a square, or an X shape, or a long narrow rectangle is just a puzzle that takes five seconds to solve and fifteen minutes of drudgery to execute.

I'd much rather have a Defense Grid style with intelligent towers and maybe some UI controllable weapons.

H.

You're not quite right.

For TD games that have strong short range or strong aura/pulse effect towers, or TD games that are heavily money constrained or which stack tower upgrade power logarithmically or some other "greater than linear" fashion (top level "special" tower upgrades that emphasize damage or effects over range), etc, certain kinds of helical shapes turn out to be best (basically you get to expose the maximum number of creeps to the maximum number of towers simultaneously in a small space, using fewer towers.)

If the TD game has "amplifier" type towers, again, the longest linear maze is probably not the way to go.

(I am, for the record, not a fan of juggling, and think that it's pretty much the worst mechanic in bad TD games. So I agree with Houngan on that, ultimately)

[Tim James]

I don't follow tower defense games, but reading this thread I thought of something in reference to avatar control:

Toy soldiers handles this much better, with the ability to take control of any cannons if you want to (more for fun than anything), but if you leave them alone they kick ass toocliffski, did you enjoy Men of War? Have you considered occasional direct control of the units?

The reason I ask is because it might be a nice way to leverage the war angle. I'm no wargame expert either, but I think part of the appeal is stories about improbable heroic actions leading to victory. Taking control of a unit every now and then might help players write their own story on each map. A lot of people said they don't like avatar control so it could be limited to an infrequent ability rather than a constant requirement.

That got me thinking about other ways to leverage the war angle. What about assigning random names to the commanders of each unit? Since they take damage, players might form an attachment to units that survive deep into the campaign. Kind of like XCOM -- they start out as faceless units but after a while you cringe when one goes down. This also brings to mind the idea of a retreat button on the attacking side, but I suppose that goes against the WWI caricature of sending waves to their death.

I don't want to try to design your game in a forum thread, and maybe this is all inappropriate when you have hundreds of videogame units like giant cannons instead of a handful of machinegun teams and tank commanders. Most ideas gamers have don't work well in the end. But you said you'd like to make yours different so perhaps this will help you brainstorm. I also mention it to share my angst about tower defense. I've never cared when playing these games. Wargame hooks might help with that.

[snowcrash22]

Are these unique ideas (I don't know)?
-Destructible terrain (small intermediate sections) that once mined yield resources to build towers and sculpt out maze junctions, instead of just walling them off.

-Combine the unique music level mechanic of Beat Hazard to the pathing and composition of the mobs.

[TranquilityBase]

Wow, that would be awesome. The creeps are marines, and you are an alien "growing" defenses in the walls of your ship. Beware the Dermal Sphincter!

When I think X-COM tower defense, I picture waves of alien creeps causing the newbie towers to panic and start shooting each other.

[cliffski]

cliffski, did you enjoy Men of War? Have you considered occasional direct control of the units?


It's a possibility, maybe for a later patch, because the current game is too big for me as it is, but looking at the game right now, I'd love to be able to occasionally control a mech or a tank. Maybe a cannon-fodder style ipad spin off game? :D

On the subject of my tower defense experimentation, I coded a system to record all the attackers unit placements (when playing on the creeps side). I need this anyway, so I can put together pre-scripted attacking AI for people who don't want adaptive AI...

... and this led me to realise that you can play as attacker, save out your very own attacking play record, then play against yourself in defense mode.
Which seems kinda cool to me, but I'm probably missing something fundamental that means actually that would suck right?