Minecraft wiki entry for Spawn, associated text: Mob spawning in bedrock edition happens within a spherical shell 24-44 blocks away from the player on simulation distance 4. It happens a quasi-spherical shell 24-128 blocks away from the player, restricted by a simulation distance and/or to roughly 96 blocks horizontally, on simulation distances 6 and higher. This means that mobs can spawn directly above or below the player (for example, phantoms in the sky or zombies underground). Mobs can spawn only in chunks that are being ticked. There is a 11⁄2000 chance of the mob spawning algorithm attempting to run per chunk, per tick.