A ladder is crafted out of 7 bamboo or sticks. To craft a ladder, place bamboo or sticks in an "H" shape in a 3x3 crafting area, 3 vertically on each side, and 1 in the center. Afterwards, you will get 3 ladders of out that.
Ladders can be placed one above the other, and the player can then go up and down. If falling, the player can land on a ladder and they will descend at a normal rate without taking fall damage.