Activate the pistons every 20 seconds. The blazes drop into the tube. Hit them once. 10 XP per kill.
: A standard setup can take a player from level 0 to 30 in roughly 4 hours of AFK time, though larger "5-furnace" arrays can reduce this to 45 minutes. Comparison Table: XP Farm Efficiency Preparation Level Best Feature Skeleton Spawner Early-Mid Game Provides Bones/Arrows + steady XP Zombie Spawner Early Game Easiest to find in caves Enderman Hole Very fast XP once you reach the End Cactus Smelter Works in Peaceful mode; fully automatic Key Build Tips for 1.7.10 minecraft 1.7.10 xp farm