Calamity Mod Wiki
Boss Effects
Boss Effects.png
Type Debuff
Effects Reduced spawn rate by 80% and maximum spawn count by 99.9%.
Tooltip The active boss is reducing spawn rates...a lot

Boss Effects is a debuff that is active while any boss is alive. It functions as a stronger version of the Zen buff, reducing spawn rates and maximum spawn count by a very high amount, in order to ensure that the boss fight has no interference from unrelated enemies.


  • Despite technically being a boss, the Martian Saucer does not activate this debuff. This is to prevent it from interfering with the rest of the Martian Madness event.
  • The debuff will not be applied for bosses from other mods.


  • Despite the debuff not being visibly active, its effects are applied during the gap between The Devourer of Gods's two phases.
  • This debuff was previously named "Boss Zen".