minecraft-java-edition
I have made a 50×50 mob trap as specified in this tutorial. Every time I enter the area, mobs spawn inside of the trap, but after they die, no more appear. What am I doing wrong?
The floor of the trap is at y = 67 and the collection point is at the side of one of the edges of the trap at y = 54. Is my collection point affecting the mobs spawning?
The rules for "normal" spawns do not seem to apply fully to Mob Spawners. A dungeon with a completely flooded floor is not safe. Apparently the random block in the 9x9x9 cube can be air.
Here's a flooded dungeon, and here's the same dungeon after I turned the difficulty to Easy (and removed the torch). The spider spawned in the water and climbed up to the ceiling.
Edit: Test repeated with source blocks, and a torch for better visibility.
I know this is an old question, but it came up in a Google.
It has recently been theorised (and to a certain extent proved) that there is a bug related to mobs spawning on the edge of the loaded chunk area, wandering out and still using up the mob limit.
Further analysis and experimentation is available in this video.
Best Answer
Depending on whether you consider it "cheating" or not, you should find out if there are other caves nearby that are consuming your mob cap.
If you press F3 in game to get the debug menu and look at the value for E on the second row. This will tell you the number of entities (including mobs) that are visible/in-game. If the second number stays high when all the mobs in your trap have died, then it is likely they are spawning elsewhere.
Spawn region is roughly 272 x 272 around the player, with a 24 block sphere (yes they apparently do exist in MC) around the player excluded from possible spawning. This means if there are any dark spots in that region, mobs will amass there and your mob trap will die out.
If you want to take the "cheating" a little further, you can use something like minutor to show you the caves in your map and head out to light them all up. You'll also need to light up the ground in that 272 x 272 region as well.
This is why building a high rate mob trap "legit" is a pain in the ass! I'm amassing TNT to destroy the entire 272 x 272 area down to bedrock, that should stop them spawning :)
NB: I use the word "cheating" lightly, it's your game, play it how you want.