Slow Fall

At 4th level or higher, a monk within arm's reach of a wall can use it to slow his descent. When first gaining this ability, he takes damage as if the fall were 20 feet shorter than it actually is. The monk's ability to slow his fall (that is, to reduce the effective distance of the fall when next to a wall) improves with his monk level until at 20th level he can use a nearby wall to slow his descent and fall any distance without harm.