A monster spawner spawns monsters.
To spawn monsters, the player needs to be very close to the spawner. It spawns mobs in a radius of three blocks from the bottom right corner of the monster spawner, however it can spawn mobs up to two blocks above or below this area (see the picture below). However, the mob may be partially outside this area when it spawns, because skeletons and zombies require a 1 by 2 space to spawn, and spiders require a 2 by 1 space to spawn, and only one of these has to be inside the area for it to spawn.
It can spawn monsters on any solid block within the spawning area (or two blocks above or below), if the area is not obstructed by solid blocks. They are not kept from spawning by non-solid blocks, such as water and backdrops. If the whole spawn area is obstructed by solid blocks, monsters will not spawn.
Every 10 seconds or so, the spawner tries to spawn a monster. It can spawn up to two monsters. After that it will spawn no more until they are killed or they despawn, no matter how far away they go from the spawner. Monsters that have not been spawned by the spawner do not add to this mob cap. This is to prevent lag and dungeons and skyhold spawner rooms becoming too difficult to raid. If the monsters were killed instantly, the monster spawner could have a 1 in 160 chance of spawning a monster every second.
It is possible for the player to use monster spawner mechanics to their advantage and use it to kill monsters to collect their drops and experience.
For maximum efficiency, the player should kill the monsters as quickly as possible, so that the next monsters can spawn. Having more spawning space doesn't seem to speed up spawning, so it is better to have a small area in which they can spawn, so that the player can kill the monster quickly without having to move themselves or the monster to them.
To make it dark, the player can build the farm underground (or high up in the sky) or use odd torches, which create darkness.
|Unknown version||Release date unknown||
|1.23||Oct 31, 2012||
|1.26||Mar 28, 2014||
|1.26.4||May 31, 2014||