Tower defense as a genre

Published on Monday, March 18, 2019 By Brad Wardell In Siege of Centauri

Stardock's own Callum McCole wrote this.

Let's talk about how towers should work.

TD Design Pillars - Meaningful Tower Variety

For positioning and composition of towers to be meaningful, they need significant differences in their utility and characteristics, typically in the form of what creep types they are strong against but also other modifiers such as range, damage-over-time, splash damage, minimum range, and many other quirks. These quirks should be intuitive for the weapon type and VFX of the tower, such as Flame Towers doing splash and damage over time rather than a gun tower.

You should need to mix multiple different tower types together, instead of just spamming 1-2 towers types, but this requires good map design. Maps should also be designed where some towers perform better than others so that each mission becomes a new challenge and you can’t just default back to the same strategy that you used on previous missions.

Almost no Tower Defense game has a super tower, as having the ultimate tower would remove any strategic consideration. While TD’s have towers that are more expensive and powerful, but they still have weaknesses and can serve only as part of a wider tower composition.

Tower upgrades can be more interesting if they have specific bonuses the player has to choose between such as Increased range or Increased rate of fire. Upgrades should also take time to implement putting the tower out of action, making timing of the upgrades important.


Core Tower Archetypes Found in Tower Defense Games:

  • Gun Tower - Standard rapid firing weapon
  • Burn (Laser) Towers - Single target damage over time. Doesn’t stack.
  • Flame Towers - Short range splash. Weak single target.
  • Artillery Tower - Long range indirect fire with splash
  • Frost Tower - slows enemies in a cone with attacks
  • Railgun - Slow firing armor-piercing attack strong against heavy targets.
  • Shock tower - single target slow or stun with good range
  • Glaive Turret - Bounces between targets
  • Anti-Air Flak - Medium Splash Damage against air.
  • Anti-Air Missile Tower - Long range strong single target damage
  • Boost Tower - Buffs rate of fire or damage of nearby tower
  • Rocket tower - long range, slow moving projectile but explodes with splash damage. Accurate
  • Tesla Coil - Damage increases the longer it can charge up between attacking something

Additional Tower types and utility

    • Debuff aura - reduces armor of nearby creeps
    • Slow Aura - Slows all units around it rather than units it attacks.
    • Minigun - Damage increases the longer it maintains focus on a single target
    • Prism Tower (Red Alert 2) - Can bounce attack off other nearby Prism towers to get bonus damage.
    • Pillbox - Does damage to targets all around it instead of a single target.
    • Heavy Machine Gun Bunker (Company of Heroes) - High constant damage but can only fire in a small arc forward
    • Blocking Towers - Spawns objects that impedes creep movement
    • Wall Towers - A cheap tower with no attack specifically for funneling enemy around key positions.
    • Nuclear Tower - Damages friendly towers near the blast, needs to be placed to avoid doing that
    • Salvage - Collects extra resources when destroying creeps (or when creeps are destroyed near it)
    • Critical Chance - Tower has a chance to do additional damage. Or just has RNG based damage.
    • Overcharge - Dangerous burst but then has a long cooldown. Needs to reload it’s clip.
    • Snare - Casts single target snare (stops it from moving)
    • Evolution - Gains a small bonus every unit it kills or after x amount of damage dealt
    • Stun Tower - Stuns all enemies around it for a short duration every x seconds
    • Summoning Tower - Automatically summons drones, or spawns them off creep kills
    • Weaken tower - Reduces cree’s max health and health regeneration but does little damage


  • Logistics Tower - Decreases the cost of building and upgrading towers around the Logistics tower.
  • Boomerang tower - Fires a projectile that spins around hitting any enemies it goes through. Should be placed around corners from a certain angle.


What are some of the other kinds of towers you could imagine seeing?