- For strategies on defeating a Dungeon Guardian, see Guide:Dungeon Guardian strategies.
Dungeon Guardians are enemies that guard the Dungeon against intruders. If a player enters the Dungeon without first killing Skeletron and travels below zero depth (a horizontal border separating the surface from the underground), one or more Dungeon Guardians quickly fly at the player, dealing 1,000 damage each, which effectively kills most players instantly. Dungeon Guardians are large, very fast, and travel through all blocks.
- If you are unlucky with a Teleportation Potion, and you are randomly teleported into the dungeon before fighting Skeletron, Dungeon Guardians will spawn. Due to the enclosed nature of the Dungeon, your chances of survival are slim.
- To be considered in the Dungeon, you must be in front of a dungeon wall. Simply having a large number of dungeon bricks on-screen will not count as being in the Dungeon.
- Killing a Dungeon Guardian is possible, though it would take thousands of hits due to its absurdly high defense. Combined with the fact that you generally need to contend with multiple Guardians at once, victory is extremely unlikely unless you prepare carefully for the encounter.
- Entering the Dungeon while fighting Skeletron will still spawn the Dungeon Guardian.
- If you're lucky enough when wearing a Master Ninja Gear you may be able to dodge its attack.
- It is possible to survive a Dungeon Guardian using Beetle armor (with shell), defense + warding accessories and Ironskin and Well Fed buffs and 500 life. The guardian may hit 500 hp, which will kill you in one hit. Sometimes he will hit somewhere in the 480s and you will survive, you can reduce this damage further using Endurance Potions, a Lifeforce Potion and having a friend with a Paladin's Shield equipped.
- For tips on fighting the dungeon guardian, see Bone Key.
- Originally, actual Skeletron Heads were used to guard the Dungeon. Killing all Skeletron Heads would count as defeating Skeletron, so the Dungeon Guardian was created to repair this unintentional behavior.
- The AI-reset problem has now been fixed, causing Turtle armor to no longer deal massive damage. The damage is now reduced to 1, like all other attacks.
- Defense raised from 9000 to 9999.
- 22.214.171.124: Damage reduced from 9000 to 1000, to prevent Turtle armor from dealing too much damage, however the exploit still works due to the Dungeon Guardian's AI resetting the damage (see [Discussion of this exploit] for details).
- 1.2: Now drops a Bone Key upon death.
- 1.0.5: Introduced, replacing Skeletron Heads as the Dungeon's guards.
- 1.0.5 Patchlog: “Entering the dungeon before defeating Skeletron now spawns a new NPC instead of Skeletron’s head. This should fix several issues with that event.”