Due to its unattainably high attack and defense, the Dungeon Guardian will always take 1 damage from all attacks (except criticals, which deal 2 damage) and will kill any player in one hit unless they have the Master Ninja Gear or Black Belt which has a chance to dodge attacks. A player with max HP and the maximum Beetle Endurance Buff may survive one hit from this monster as well, and an extended version of this strategy can be used to survive two hits, or one in Expert mode. Even if a dungeon guardian is killed, access is still not allowed in the dungeon as more and more guardians will appear each time you kill them.
Before the Dungeon Guardian existed, there were numerous Skeletron Heads which is just Skeletron without the arms. These heads fulfilled a similar role but can be killed easily and didn't kill the player in one hit. Unlike with the Dungeon Guardian, killing all of the Skeletron Heads after they appear will grant the player access to the Dungeon as if they had killed Skeletron normally. The Dungeon Guardian was presumably introduced to counteract this unintended behavior. Defeating it does not allow access to Dungeon despite it looks like Skeletron without arms.
Due to the high defense of the Dungeon Guardian, it is best to use armor/accessories that boost your critical strike chance rather than damage, and use a rapid hitting weapon such as a Megashark or S.D.M.G. with Crystal Bullets to increase the number of times you hit it.
- One tactic that can be used to kill the Dungeon Guardian (post 1.2) is to make a skybridge out of Asphalt Blocks. Run on the asphalt with Hermes/Flurry/Spectre/Lightning Boots in order to maintain a faster speed than the dungeon guardian. Get four Teleporters and set them one on each end and then an other 60-70 blocks away from the one nearest to the edge. Put a pressure plate on each of the edge teleporters and wire them so that once you step on it, you teleport in the opposite direction.
- Another useful and common tactic is to wear Frost Armor and use 3-4 Gravitation Potions, any rapid-firing weapon and Chlorophyte bullets, wearing Wings and reforge all your accessories so they grant maximum critical chance. Activate your Gravitation Potion, dig a straight line into the dungeon, and once you hear the sound you hear when summoning any boss you press the "Up" button (Default on W), flap your wings very shortly so he can catch up and start firing at it. To make distance between you and the Dungeon Guardian you wait a bit longer before you flip back and forth using your Gravitation Potion, and to close the distance you keep it fast-paced.
It will take you around 7-10 minutes and if you combine this with Ammo Reservation Potions and an Ammo Box, you (most likely) only need your ammo bar full of Chlorophyte Bullets and (most likely again) still have a nice amount of bullets left.
- You can also use the Piranha Gun and Frost Armor, since the Dungeon Guardian is affected by Frostburn and the Piranha Gun latches onto the Dungeon Guardian, making it easier because you don't have to aim and the fact that Piranha Gun does not consume ammo, however, you need to be close, else the Piranha will return and need to be fired again.
- A cheat-styled yet effective way to farm for the Bone Key is to make a Hoik, which is a teleportation exploit that allows players to shift through ramp blocks into other teleporters, etc.
- To defeat the Dungeon Guardian in early hardmode without too much hassle, crystal bullets can be used in a minishark while flying over a skybridge, making sure to move diagonally in midair to keep yourself going faster. this tactic is easier with a Shield Of Cthuhlu, as you can fly over the dungeon guardian and turn around with ease. This tactic requires moderate dodging skill, and can take out the Dungeon Guardian in around 5-7 minutes.
- Also note that using offensive summons can provide an extra (small) bit of damage
- It is effective to use bee weapons such as The Bee's Knees, Bee Gun, or Beenades since they will do sustained damage while they chase after the Dungeon Guardian.
- Using the Laser Machinegun with alot of mana potions and full Nebula Armor could be useful because of how many bullets the Laser Machinegun fires.Another Strategy is using Razorpine or S.D.M.G or Megashark because of the rapid speed.
- The Phantasm with Luminite Arrows and the UFO mount is very effective against the Dungeon Guardian, because of the buildup that can easily drain its health. You can also use Frost Armor, max critical chance and a Rapid Chain Gun to defeat it easily within 90 seconds.
- A way to kill the Dungeon Guardian safely is to use heart arrows and maybe one frostburn arrow to speed up the process slightly, sacrificing some of the chances of it not hitting you and, unless in certain circumstance, kill you immediately.
- It is advised to use Titanium Armor due the fact that it grants you the ability to dodge his attack once every 20 seconds.
- If the player is in an underground tunnel that is close enough to the dungeon (but not actually in the dungeon proper), the Dungeon Guardian may spawn anyway and kill them. The only way to avoid this would be to defeat Skeletron.
- Multiple Dungeon Guardians may spawn if the player ventures too far into the dungeon without killing Skeletron.
- The maximum number of Dungeon Guardians that can spawn at one time is 14.
- It can also spawn directly on top or below the player.
- The Dungeon Guardian has no death animation, sound, or corpse which indicates that it is not meant to be killed. However as 1.2 update, the dungeon guardian will drop a Bone Key (Summons a Baby Skeletron Head) which indicates that killing it may give you great rewards.
- The Dungeon Guardian is actually a re-scripted version of Skeletron's head, but is more like when Skeletron is alive during the day.
- Despite its sky-high attack and defense, it is actually possible to defeat this monster, though you must take special precautions to enter the dungeon in such a way that you can escape quickly after spawning it.
- The easiest way to go about defeating it is by using a Minishark or Megashark (the difference is minimal due to the monster's defense) loaded with Crystal Bullets. Use any items that allow you to fly or move quickly (Wings, Gravitation Potions, Hermes Boots and Swiftness Potions on a Skybridge, etc.) and shoot at it, taking care to avoid direct contact with it. This will take a while, but there is no way around that.
- When it comes, the boss summon/special attack sound appears, despite the fact that Dungeon Guardian is not a boss. However, this is likely due to it's absurdly high health and defense.
- If two people are on a server, it is possible to summon Skeletron and attract the Dungeon Guardian at the same time. If these two interact with each other, the Dungeon Guardian will defeat Skeletron. This will render a glitch in which Skeletron is already defeated, however, the Dungeon Guardian is still active in the dungeon, rendering it impossible to access the dungeon until you kill the Dungeon Guardian itself.
- If you are close to the area of the Dungeon where the Guardian will come out and kill you, but you aren't in the dungeon itself but underground near it, he may go through the dungeon walls and kill you.
- If you are wearing Turtle Armor when the Dungeon Guardian attacks you, it deals 1000 damage, instantly killing you. But due to the Turtle Armor's high thorns effect, it gets dealt 9999 damage instead of 1000 damage, and dies as well.
- Dungeon Guardian will now despawn if too much distance is put between player and mob.
- Lowered Attack to 1000.
- Now drops a Bone Key upon defeat.
- Added to the game.