Caster AI

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Caster AI is an AI followed by the caster class of enemies. Casters move exclusively via teleporting, and fire slow-moving projectiles that travel through blocks.

Caster enemies

Enemy Projectile Biome
Dark CasterDark Caster Water SphereWater Sphere Dungeon
DiabolistDiabolist Inferno Dungeon
NecromancerNecromancer Shadow Beam Dungeon
Ragged CasterRagged Caster Lost Soul Dungeon
Fire ImpFire Imp Burning SphereBurning Sphere Underworld
Goblin SorcererGoblin Sorcerer Chaos BallChaos Ball Goblin Invasion
TimTim Chaos BallChaos Ball Cavern
Rune WizardRune Wizard Rune BlastRune Blast Cavern
Desert SpiritDesert Spirit(Desktop, Console and Mobile versions) Desert Spirit's CurseDesert Spirit's Curse Corrupted/Crimson Underground Desert


Casters always perform the following actions in succession:

  1. Check for a location to teleport to, that:
    • is within 20 tiles from the player, but at least 4 tiles away
    • contains a space free from solid blocks that is at least 4 blocks high and 3 blocks wide
    • does not contain lava
  2. Teleport to a random valid location, if there are any
  3. Fire 3 projectiles towards the player in succession
  4. Pause for about 3 seconds after firing
  5. Check for other valid teleport locations, beginning the cycle again.
  • Dungeon-based Casters will only teleport to spaces containing any variant of naturally-placed Dungeon Brick Wall, effectively preventing them from teleporting anywhere outside of the Dungeon.
  • If damage is taken while firing, a Caster will stop firing and begin the 3-second pause immediately, followed by a teleport.
  • If damage is taken during a 3-second pause, the pause countdown is reset back to 3 seconds, followed by a teleport. Taking repeated damage will continuously reset the countdown timer and prevent the Caster from moving or firing.
    • Necromancers and Diabolists teleport as soon as they take damage, so it may be difficult to defeat these enemies with low-damage weapons.
    • Ragged Casters will not teleport immediately after being hit, but they have no delay between teleporting and firing their shots.
  • Casters will never walk or jump. Their only method of movement is teleporting (aside from knockback from being attacked).
  • Casters' projectiles travel through all block types, except those fired by Necromancers.
  • Chaos Balls fired by Goblin Sorcerers and Tim, Water Spheres fired by Dark Casters, and Burning Spheres fired by Fire Imps can be destroyed by a single hit from any weapon or tool.


Using a fast weapon which attacks continuously while holding the attack button makes for an effective shield against Casters' projectiles. Weapons like the Muramasa will work perfectly (even pickaxes, hammers, or axes will work reasonably well, as their swings similarly do not require individual clicks). An Inferno Potion also blocks their projectiles.

The Death Sickle, Mushroom Spear, Chlorophyte Saber, Crystal Vile Shard(Desktop, Console and Mobile versions), or the Nettle Burst are effective both for taking down projectiles and attacking Casters, since they are powerful weapons and can travel through walls. They have the best chance of stopping projectiles early, being capable of taking down projectiles at a reasonable distance even when they are coming through a thick wall. They are also good for attacking Casters when they are out of reach due to teleporting behind walls.

After Casters have fired their 3-projectile volley, there is a 3-second gap until they teleport; this is the perfect time to attack. Once you have started attacking, make sure you do not stop for too long, or else they will teleport again. Repeated attacks prevent Casters from firing or teleporting away.

Sometimes it is best to shield off their attacks when they are far away or in a hard-to-reach area, and wait until they teleport within attack range.


  • Desktop 1.0.5: A longer delay was added between the 3-shot volley and the next teleport.