Minecraft wiki entry for Iron_golem_farming, associated text: The average lifetime of iron golems depends on transport time and kill time. Most farms use water to transport and lava blades (lava suspended on collisionless blocks such as signs or open fence gates) to kill. It is also possible to use rail systems, although rail systems are likely slower than water. Other kill methods such as magma blocks, skeleton arrows, and trident killers are slower than lava. However, trident killers can kill faster than lava if the tridents are enchanted with Impaling V and the iron golems are kept in contact with water. Note that if you use a trident killer, you do not gain experience, and you cannot use Looting.