Allows Isaac to walk across gaps one square across by automatically placing a ladder between the two walkable sections. Enemies can not walk over the ladder.
Jacob and Esau: both characters can walk over the ladder, but only the character with the item can place it.
In-game Footage
Trivia
This item is a reference to the Ladder in The Legend of Zelda for the NES.
This item can be found as one of the Nintendo-themed Treasure Room items in the 6th of December's Daily Run, which is an homage to the late CEO of Nintendo, Satoru Iwata.
Bug
Bug!
In co-op, fellow players can stand on the ladder. If they do this and the player holding the item walks to another ledge, the ladder beneath player 2 will disappear, allowing him to walk on air.