I've noticed a bunch of rules regarding monster behavior relative to player position: they don't spawn near the player, spawn then despawn far from player, spawn and stay somewhere in between, move in certain distance, don't move at a different distance... generally, a mess of rules I can't quite tackle. So, I'm building a mob grinder. From what I understand, if I'm too close monsters won't spawn, if I'm too far they will despawn and if I'm not near enough they won't move, won't fall in the flow and get carried to the collection zone.

So, where should my character be, respective to the designated mob spawn area of the grinder for optimal yield?


Mobs won't spawn closer than 24 blocks. They won't move around when farther than 32 blocks. Those are the only rules you need to know for a grinder that relies on mobs walking around.

The inference is straightforward: you want your collection spot to be 24 metres away from the nearest wall of the grinder, and you want the far wall of the grinder to be 33 blocks away.

Or put another way, you want your grinder to be in the 8-metre-thick ring or shell around the player where mobs will spawn and move. In this illustration of the spawning distance rules, this thin shell of viable spawning area is represented by the light blue ring:

Mob Spawning Ranges: Spherical regions centered on the player

This implies that the optimal grinder is shaped like a ring or a ball surrounding the player. (Note that these distances are true radii, so if the grinder is above you in need to be closer than 24 horizontal metres!) Construction considerations make such a design less than optimal though, so a nice compromise is one to four towers that each fully enclose a section of the useful spawning shell; even if some of the floor space is "dead" sometimes, the less-perfect design allows you to move around in your collection zone a bit more and still have the grinder(s) work well.

  • What happens in the green area? – Steve May 11 '13 at 22:48
  • @Steve Nothing. Normal mob spawning doesn't happen, is all. For normal mob spawning, you can also ignore the yellow circle. – SevenSidedDie May 11 '13 at 23:58
  • 3
    I used a bit different approach. A grinder with the "player house" at altitude of 200 (to exclude all land and underground spawns), over the sea (so that falls aren't fatal), shaped as a dome some 26m radius with the house in the center. The dome is covered with a roof (lit) and walls, and the narrow zone between the walls and the dome is filled with water flowing to "monster collector" channels pushing them towards a fall-based XP grinder. – SF. May 16 '13 at 7:38
  • 2
    Is this still up to date? – Tim Feb 18 '15 at 20:44
  • @Tim I'm unaware of any change to spawning mechanics. That would be kinda a big deal. – SevenSidedDie Feb 18 '15 at 23:39

I made grinder at very high in sky, but for me it feels that even if grinder is above you 50 meters, you still have to move horizontally 24 meters away or it doesn't spawn monsters at all. Monsters start spawning immediately when I move away.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.