Skeletron


 * "Please, no, stranger. You'll only get yourself killed!"

Skeletron is a Boss that must be defeated before traveling through the Dungeon. It is immune to the Poisoned, On Fire!, and Cursed Inferno debuffs.

Defeating Skeletron grants unlimited access to all Dungeon areas for all players. It also causes the Clothier NPC to spawn, as long as a vacant House is available.

If you enter the Dungeon before killing Skeletron, Dungeon Guardians spawn once you reach 0 depth, generally killing any player with a single hit. Additionally, if the Dungeon Guardian is killed, access is NOT allowed to the Dungeon.

Summoning
Skeletron is summoned by speaking to the Old Man at the Dungeon's entrance, at night, who will die and spawn Skeletron when you select the “curse” option. If you speak to the Old Man during the day, he will ask you to return at night. You will only be able to summon Skeletron once per night, as the Old Man will not respawn until day.

Skeletron can be summoned repeatedly this way until it is defeated. Once it is defeated, the Old Man will no longer appear. Skeletron can be re-summoned thereafter once the player acquires the Clothier Voodoo Doll. Equipping the Doll allows the player to kill the Clothier, which summons Skeletron.

Attacks
Skeletron is a large floating skeleton head with two independent floating hands. All parts can travel through blocks, and will attempt to make contact with the player to inflict damage. Each part can be killed independently, but killing the head is all that's required to defeat Skeletron.

Skeletron alternates between two attacks:


 * The head remains above while his hands slash at the player.
 * The head spins, dealing significant damage, but its defense drops to zero.

Skeletron has an additional attack in expert mode:


 * Skeletron's Head is near invincible, but after losing either of his hands his head becomes vulnerable and will begin to shoot homing skulls resembling Cursed Skulls at the player, increasing in frequency as his health gets closer to 0.

If the player takes too long to kill him and dawn arrives, Skeletron will act like a Dungeon Guardian, performing a head spin attack with very high damage, which will usually kill any players remaining in the vicinity quickly (it is still possible to kill him, but players are at an extreme disadvantage).

In Expert Mode, Skeletron moves faster and has better A.I. when targeting multiple players. He's also able to inflict several debuffs: the hands inflict Slow, while the head inflicts Bleeding.

Tips

 * With multiple players, it's a good idea for softcore and mediumcore characters to set up a Bed near the Dungeon, so that they can simply rejoin the fight if they die.
 * If you use a Magic Mirror, Skeletron won't follow you back to your spawn, and despawn instead.
 * In expert mode, Skeletron has over 100 defense until you defeat the hands.
 * Don't jump onto Skeletrons head multiple times with the Slime Mount, as going too high will cause him to despawn. (Also if you enter space the slowed falling will make it almost impossible to       get back down past him.)
 * Going fast enough on a minecart can cause the hands to despawn, leaving only the head to fight.

Trivia

 * Assuming that the player is at 5 ft. 9 1/2 in. heightwise, Skeletron's Head would be about 11 feet tall and 8 feet wide. The Hands would be 10 feet tall and 7 feet across.
 * Skeletron Heads used to protect the Dungeon, but when one was killed, it would count as killing Skeletron, so they purposed the Dungeon Guardians to protect the Dungeon instead.
 * With his hands combined, Skeletron has even more health than the Expert mode Wall of Flesh.

History
Skeletron Скелетрон