Hostile mobs in Minecraft 1.20 only spawn at light level 0 on the block where they appear in the Overworld and Nether.

Quick Scoop: What light level do mobs spawn in 1.20?

In modern versions (1.18+ through 1.20), Mojang simplified hostile mob spawning: instead of any light level 7 or below, the game now requires complete darkness.

  • Hostile mobs (zombies, skeletons, creepers, spiders, etc.)
    • Spawn when the block light level is 0.
* Any light source that raises that block’s light to 1 or more will prevent spawns.
  • Why it feels different from old versions:
    • Before 1.18, mobs could spawn at light level 7 or lower, so you needed a lot more torches.
* Now, a single torch covers a much larger safe area since it just has to remove all level‑0 spots.
  • Caves vs surface at night:
    • Underground caves often reach true light level 0, so mobs spawn there very reliably.
* On the surface at night, some blocks can still be above 0 due to sky light and the moon, so not every dark-looking spot actually allows spawning.

Practical tips for 1.20

  • Place torches, lanterns, or other light sources so there are no blocks left at light level 0 in or around your base.
  • Check the “Client Light” or similar debug info (F3 on Java) and make sure the block you’re standing on shows at least 1 for light.
  • When building mob farms, ensure the spawning platforms are kept at light level 0, and any unwanted areas are lit so they don’t compete with your farm.

In short: in Minecraft 1.20, if a block ever reaches light level 0 and meets the usual spawn rules (correct block, space, biome, etc.), hostile mobs can appear there.

Information gathered from public forums or data available on the internet and portrayed here.