How to improve your Tower Defense

Level 6
May 13, 2009

How to improve your Tower Defense

1. Towers The biggest difference between a good tower defense and a lousy one is usually the towers. Although the towers in the map are not everything. The amount of towers in a tower defense adds difference to the gameplay, if designed well that is. But then what is they key to good tower design? There is no written law or code that we follow just plain logic and understanding. What sounds best for a tower: a pitch black "grunt" or a slightly color adjusted undead necromancer with a glowing staff? Tower designing is mostly about common sense and ingenuity. A tower is basically: a model file, a missile, body type and abilities. If you have for example an aquatic theme add that to your mind when designing. If you have a fast unit use a tiny and fit character like a troll but if you want a slow powerful unit use an ogre or a mountain giant. Choose a fitting missile, for the troll you might wanna use Rexxars axes but for the mountain giant you use rocks or melee damage instead. For added variation use upgrades and abilities.

Many map makers forget about the sound effects, I just found out that all my towers sounded like ancient protector.
Randomness is not always a winning element, a lamp post throwing murlocs on the enemy is just plain weird.
Be sure towers can't hit creeps on other lanes/areas.
Don't have the same model file for all towers, you can't tell them apart nor is it good for your eyes either.
A neat trick I just learned is to add a special effect to a unit, modify the sphere ability and you can equip your units with items and fire enchants.
Different ground texture is rare on towers, like undead texture for demons. [Rare]
Hero towers are rarely used, I have not found any maps with a good hero tower but this doesn't mean you shouldn't try it. [Rare]

Good examples: Experience TD, Power Towers
Bad examples: Green TD, almost all mauls.

2. Builders You need something that builds your towers usually it's just an undead acolyte with different stats, but like Skibi TD you have a hero that can use it's abilities to ease your task. Something important when using hero's with abilities think about which abilities actually fits, mass stun and slow aura are alright but charge or death coil is maybe not what we are searching for. Another way is to do like in blizzards tower defense: you build more and more builders the longer you play. If you put a price on the builders you can give the players many different ways to play your map. You can also do as gem TD and have an original variation. Different builder picking ways are very rare, usually it's just a tavern. You want to spawn some ideas around here. A nice thing you might wanna add to your map is a place outside the map where you can see all the towers stats and abilities. Do it so when you select a tower it gives it to you temporarily so you can see it's stats.

Sound, yet again.
Fly height isn't always beautiful.
Remove pathing so it is unable to block and can walk through your towers, an option instead of flying.
Anti-stuck ability is always nice, remember those horrible waiting times when you played mauls?
Attack and abilities on the builder is rarely used. [Rare]

Good example: Skibi TD
Bad example: Green TD

3. Terrain A straight line is not original but might be hard; a turn is easier and a more varied in TD designs. A good option here is to let the players decide which terrain type to use, like in experience TD. Pathblocking is something I often forget, this prevents players from building on other players lanes/areas in single race which might bug the map. Also the eye candy on the sides are important, but might be distracting. Remember that terrain is a big part in a TD. There are more types of terrain then line and turn, like spiral or snake. You get the point, you don't have to use the classical way.

If you use nodes make the node region unbuildable with a rock tile for example or lame people might build over it.
Variation in the lane/area ground is rare, so is weather effects. [Rare]

Good examples: Element TD, Experience TD, Power Towers
Bad examples: almost all mauls.

4. Creeps and spawn Creeps are one of the key ingredients for a good tower defense. Variation and abilities is a good way to improve the gameplay. For starters don't use the same model for all creeps, Golden rule. One of many reasons is because the player might not even know if he/she made it to the next level. How the creeps spawn and how many are different for each TD. The main types of spawning are:
The units spawn 1 by one with a short interval, as seen in Skibi TD. With flow it usually switches level automatically without break.
The units all spawn at the same time, as seen in Mauls.
The players buy creeps which gets sent to the enemy players lanes, as seen in Line tower wars.

Sound, yet again.
In flow types splash is almost useless, but in mass it's overpowered.
Remember that in mass you might want to stop the spawn killing by making the spawn area larger, out of range or the creeps invulnerable in the spawn area.
If you have flying creeps remember path blocking, other wise they fly over your terrain.
If you have invisible levels tell the players, to many times I've died and not knowing what hit me.
Creep abilities are recommended, as seen in Skibi TD.
Armor types and weapon types are ways to make your TD more complex and harder.
Anti-blocking is always hard to figure out, one way is letting the creeps kill the towers and refund the players for each tower, that's the bad way. The good way is when the units attack a tower their collision size sets to 0 and you order them to move to the end or the next node.
Army levels are rare (when for example not just a single kind of creep spawn but maybe a party of five different kinds of bandits). [Rare]

Good examples: Skibi TD
Bad examples: almost all mauls (hate spawn killing)

5. Tower defense types The main types of Tower defenses are:
The creeps walk towards the end and you build towers in a maze looking way, as seen in mauls.
The creeps walk on unbuildable surface and you build towers by the side to kill them of, as seen in Blizzard TD.
The creeps walk between nodes (regions), as seen in Gem TD.

Mazing has the problem with blocking and flying (because of the balance). But can be a little bit "routine" for advanced player since they most likely will used the "best" maze. One way to fix this is to have irregular terrain, meaning not linear. TD has down parts except very used method, it can be hard for advanced players and yet easy for beginners. Node is actually just a different kind of mazing type, with a little twist. The players often build around the nodes and maze them together, the big difference here is that you can use Unit - entering events for abilities.

The main game types are:
You play until you die, last man standing.
The player to first to finish all levels wins.
Same as above but in teams instead.

Survival can get boring, because some players might leave before someone or the team wins. Team has the same problem, it is usually more fun but if someone leaves the game can be ruined. You might wanna create an AI or something to prevent the game to end if someone leaves. Race can be super serious and super fun. Especially with abilities to make it harder for your enemies, more on that later.

Check the collision size on the creeps if you intend to make a maze/node map, this make them attack else wise.
Just because there are main types doesn't mean you shouldn't invent a new better type :) Rare

Good examples: Skibi TD
Bad examples: None

6. Life/point system The most common used system in TD's is the life system, a unit enters the end region and you lose one life called leaking. Sometimes you can buy lives or steal them to stay in the game. If you don't want to use the life system, you could always have your own. A new kind could be time based, most kills in shortest amount of time wins. Or a damage test most damage dealt to the last boss wins, tough this is not fair because of splash and abilities with bounce.
(kills/(max_lives-current_lives))X(multiplier)A score system, multiplier increases with the difficulty and/or if you pick a random race.

A system I would like to see is a arena system. Each level spawns a very high number of creeps and you kill as many as possible, with the money you build/upgrade towers. After each wave you get your net-worth calculated. You then get this much amount of gold in the arena and you buy items or potions for the gold. If you win as last man standing you get one point, first to ten points wins.

Make bosses have greater leak strength, meaning they take more lives when leaked, if you use lives system.
If it's a new kind of system be sure to notify the player about how it works.
A remake function is very handy, so you don't need to remake the game each time.

Good examples: Azure TD
Bad examples: None

7. Abilites Personally I think this is the most important part in a tower defense, because abilities differs so much between each TD.

Possible things that can use abilities are:
One example: the creeps in one level is faster than a usual creep or heals on death, as seen in Skibi TD. There are five types of creep abilities: enters, dies, is attacked, passive and time.
Tower abilities can be the overpowered splash, multishot or the usual poison, as seen in almost all TDs.
Your builder has a castable mass slow or stun, as seen in Skibi TD.
For example: after 10 minutes all towers in your maze change place. [Rare]
You can make the next wave flying for your enemy or buy lives, rare other then buying lives. [Rare]

One very important thing when you have creep abilities is that you need to tell the player what the creeps abilities do. If you for example have a creep that enters a region and gets invulnerable for a short amount of time, then you must in some way tell the player. Otherwise the player might freak out and rage quit. Towers abilities are so much more then just splash, multishot and slow. Castable abilities are usually quite annoying for the player, but can be a lot more fun then most passives. If you have upgrades you can do as Skibi and upgrade the spell as well. Builders can also have spells, these are often auras or castables.

Sound, yet again.
You might wanna try out the thing Skibi has with the tower damage.
Teleport on the builder might make your TD easier, but you need to check the lane/area and such, so the player don't build in another players lane/area.
Upgrades for your teams towers is maybe not a bad idea.

Good examples: Skibi TD
Bad examples: almost all mauls

8. Text Information about your TD is vital to a original TD, most use quest menu or a cinematic to spread information. Remember if you choose to have a cinematic, players who have already seen the cinematic might want to skip it. Colored text for stats and names is more pleasing to the eye then you might actually think. But over usage or the choice of bad colors can make your map worse. If you have different difficulty levels on the teams tell the players. When every level start you might want to add a short message like:
Level 02 - Footmen [Heavy, fast].
Level number, name of level and armor type and ability.
Tooltips are very important and should contain stats about the tower, spell or what ever it is. You usually have it like this: damage, range, speed, special features and the name which abilities the tower has. If your map lack in tooltips it has a big chance of being rejected as a map here on hive so don't skip out on tooltips or help tips.

Don't forget buffs, common mistake.
Don't forget if you change from gold or lumber to maybe clockwork parts, change the hover text.
Look for typos.
Might want to add funny tips at every level, personal favorite.
You can put color codes in unit names.
Map names accept color codes.
Story line is rare in TDs. [Rare]

Good examples: Elemental TD
Bad examples: Green TD

9. Balance/difficulty Difficulty shouldn't be that you get more lives the easier difficulty setting you choose and neither that you receive less money for selling. The reason you choose a harder difficulty is to challenge yourself, and it's not skills to wrestle with the feeling that you placed some of your towers wrong and need to restart. This can ruin the gameplay. If you really want to have 0% money back after selling add the swap spell from DotA. So you can change the place for the units. One way of making difficulty settings is Upgrades, more Hp, more Armor, faster, less gold earned, etc.

Balancing is one of the most time-taking things making a td, it takes countless test runs and yet it will never be perfect. Ability combos such as splash frost is a very good combination and then you should maybe reduce the range or damage of the unit. Poison, frost is also a very good combination. The more teams you have the more balancing there will be, same goes for difficulty levels. This doesn't mean you shouldn't make fewer teams.

Flying, check which units in each team that can hit them.
Range + damage + speed = overpowered.
Armor types is a good way to improve the difficulty.
This didn't help me, but you could try to check the DPS on your towers for easier balancing. Although DPS don't add range and abilities in the calculation is can still be a little easier balancing.
When you leak, an option could be to give the player the amount of money lost when leaking. This yields the snow-ball effect.

Good examples: Skibi TD, Blizzard TD
Bad examples: almost all mauls

10. Tips/final words Somethings that can add to extra gaming experience is to change the upkeep and interface text. Or ultimately the UI, tough think of the file size. Same goes for custom models and icons. Ask yourself if it's actually necessary to add that flying lion. Loading screen and minimap image greatly improves the first impression playing a map. One of the hardest and possibly the most important thing is the name of the TD. Don't name it "1337 DOTA TD", no one will take it seriously. Some small features to add might be a Multiboard. It's nice to see how the other players are fairing. AI players can be a very nice function in team maps tough I've never seen a TD with AI. Camera option is very personal, I personally like the original camera perspective. Items are rarely used in TD's, example the builder picks up the items that the creeps drop and give them to it's towers.

Last word, everything I say is not a law or something do as you please. This tutorial is formed as a word of advice.

Further reading:
Last edited:
Level 6
May 13, 2009
Change "Mobs" to Creeps or Monsters, there are many people who don't know what Mobs is, since it is a word from WoW.

The tutorial looks fine for me, at a first look I didn't find any misspelled word, I probably missed some but I guess not.

I'm changing it now :) There shouldn't be any typos or misspells because I checked them with word and Firefox ^^
Level 31
May 3, 2008
Pathblocking is something I often forget, this prevents players from building on other players lanes/areas. Also

This isn't entirely necessary for most TD cause some TD use cooperation such as Azure TD and Power TD.

As for your life system part, a good example would be Azure TD.

For your text part, you forgot 1 vital part called "tooltips". Each tower tooltips must have a very high specific detail to let us know what are the function such as the attack damage, attack cooldown, range, ability and so on.

Balance is the hardest to be achieve even if there is no existence of difficulty mode. It require a serious thinking and countless of testing to acquire a delicate balance, which are almost impossible to be achieve. Splash frost and poison could be fairly balance if the area of effect and everything else was correctly set.

Even though most of the info written was very basic and all it need was common sense to figure it out. But, it was still approvable since some people have the tedency not to think about it.

However, I notice some typo error in your tutorial. You might want to fix it or else the staff might leave it into pending.