: Mobs fall 21–23 blocks . A 23-block fall typically leaves them with half a heart of health, allowing for a one-hit kill with a fist or simple tool.
: Use a 43-block drop to bring them down to a one-hit kill. Note that you must build a "roof" 2 blocks high above your standing area so they cannot teleport to hit you. Essential Materials & Tips Water & Signs minecraft 1.7.10 xp farm