- "Keep other players out."
An iron door is an item created at a Metalwork Bench. It is similar to a Wooden Door in many respects, except that in multiplayer, iron doors only allow the placing player's Blockheads to pass through the door and not those of other players.
Viewed in detail, a placed iron door appears to be composed of two side-facing doors, a gap between them, and block-like surfaces before and behind.
An iron door will react to attempts to remove it as if it were an iron block, no matter the type of block it's taken the appearance of. This includes the appropriate tool and the number of strokes required to remove (thirty-two strokes from a diamond pickaxe minimum).
A Blockhead passing through an iron door's location will automatically open and close it, although special circumstances may make it appear that the door is left open. The door will always be opened away from the Blockhead opening it, and a door with a solid block on the other side cannot be opened.