Five platform mob farm

A stacked platform mob farm covered by Jumper, designed by gnembon and popularised through Shulkercraft. Five spawning platforms of top slabs inside a glass wall, dispensers flushing each one with water, and a scaffolding column carrying the signal up so a single clock fires them all. Mobs drop onto campfires at the bottom and a hopper floor feeds two chests. The material list is for five platforms and Jumper recommends ten.

• Set difficulty to hard and simulation distance to 5. Jumper gives this to almost everyone whose farm produces nothing, and it is the most common fix on the video.
• Standing at the chests stops the spawns, since mobs need 24 blocks of clearance. Put the AFK spot 50 to 100 blocks above, and going too high fails the same way as standing too close.
• To take XP as well, drop the campfires and let fall damage do the killing, then put slabs over the hoppers so the mobs cannot reach you.
• Water flooding the platform means the sources are merging. Place them one block in from the corners, and onto the surrounding glass rather than onto the slab.
• The glass wall is structural. Without it mobs spawn on the outer face, though ordinary glass is fine and stained is not needed.
• Campfires occasionally fall out, so seat them on the glass, and expect spiders to cling to the sides for a while before they finally drop.