Old Man

The Old Man is an NPC whose primary function is to summon Skeletron. He can be found at the Dungeon's entrance. When spoken to at night, the Old Man will give the player the option to "curse", which summons Skeletron. The Dungeon cannot be fully explored until Skeletron is defeated.

When spoken to during the day, the Old Man will tell you to return at night. He will also judge players with less than 300 life (15 hearts) or less than 10 defense as unworthy but still allows them to summon Skeletron.

The Dungeon can be entered without defeating Skeletron, but traveling deeper than ground level within it (below zero depth) will spawn Dungeon Guardians that will most likely kill the player on contact (see Guide:Dungeon Guardian strategies).

When Skeletron is defeated, the Old Man is freed from his curse and will arrive as the Clothier (as long as a vacant House is available), in addition to allowing access to the Dungeon.

Quotes
Only during day:

Only when you have 300 or less max health and/or 10 or less defense:

Only when you have more than 300 max health and more than 10 defense:

Trivia

 * Other NPCs will actually "interact" with the old man and engage in conversations.
 * He is the only NPC that will not defend himself and is not damaged by enemies. He also cannot be drowned.
 * He is one of only two friendly NPCs that does not have a Map Icon, the other being the Skeleton Merchant. However, he does appear as a white dot similar to an enemy.
 * Upon summoning Skeletron, the Old Man dies, which makes it seem as if he turns into Skeletron. (Due to the death animation explosion)

History
Greis Vieil Homme 노인 老人