Ladder

Ladders are wooden block decals for climbing walls either vertically or horizontally, and were introduced to the game in Infdev. They are created by arranging an H-shape of 7 sticks on a crafting table and can only be placed on the sides of other blocks. Players who want to conserve wood can place ladders every other block and still successfully climb them vertically; they can also be jumped onto, allowing the bottom of a ladder to be two blocks off the ground and still be accessible.

Like torches, a ladder occupies one block from the side it is placed and cannot be placed on glass. Unlike torches, however, they resist water and will create an air pocket. They also resist lava, and can be used instead of glass to let lava light shine through a ceiling.

It takes approximately 52 seconds to travel from bedrock to the roof of the sky on ladders.

Ladders provide a way to safely travel downward at maximum velocity (freefall). Upon entering a ladder's area of effect, the player's speed is reduced instantly to normal ladder descent speed and no damage is taken. However, care must be taken to avoid landing on the narrow top surface of the ladder.

Ladders are one of the many blocks that are broken more quickly with a sword, but still have double damage on the sword.

Like the player, pigs, creepers, and zombies can climb ladders. Skeletons are unable to climb ladders, but will shoot up if you are within firing range. It is unverified whether or not other mobs (Namely chickens, cows, and zombie pigmen) can climb ladders.

Spiders can be blocked from climbing a wall by placing a ladder at the top edge of the wall. This is because the ladder is technically a block and it sticks out from the wall enough to hinder the spider's climbing.

Crafting
Leitern