Survival Boss/Mob Modifications

Time-Based Boss Scaling

All times are relative to 21:00 UTC Friday

Boss Base Difficulty Time After Reset Until Boss Hits Base Difficulty Is affected by Anti-Rush?
King Slime 1.0 - -
Eye of Cthulhu 1.0 - -
Eater of Worlds 1.0 1 day -
Brain of Cthulhu 1.0 1 day -
Queen Bee 1.0 1.25 days -
Skeletron 1.0 1.5 days -
Wall of Flesh 1.0 2 days -
Twins 1.0 3 days -
Destroyer 1.0 3 days -
Skeletron Prime 1.0 3 days -
Empress of Light 0.8 3.5 days -
Plantera 1.1 4.5 days -
Golem 1.2 5 days Yes
Duke Fishron 1.2 5.5 days Yes
Cultist 1.2 6 days -
Moon Lord 1.0 6 days -

Considering Base Difficulty is the strength multiplier

The scaling currently applies to the boss and its projectiles only. All bosses bottom out at 80% strength at 10 hours passed their vanilla time target.

The exact strength of all bosses at a specific time can be checked in-game (in survival only) via /strength

Scaling Graph:

Player Count Boss Scaling

The following bosses are fixed at a specific number of players and will not be scaled based on how many actual players there are:

  • Skeletron Prime at 10 players

The following bosses have an additional specific numbers of numbers of players and will be scaled based on how many players there are:

  • Duke Fishron at 15 players
  • Empress of Light at 5 players

All other bosses are scaled at a minimum of 17 players. That is, the bosses do not change health until there are more than 17 players, then vanilla scaling applies.

Anti-Rush Mechanic

Anti-Rush is a mechanic which makes bosses impossible to spawn until they hit Base Difficulty time. This was made to prevent a fast boss progression in Survival.

Mob Strength Scaling

Mob Scale
Bone Serpent x3
Hellbat x1.8
Lava Slime x3
Fire Imp x2
Burning Sphere x3
Demon x3
Blazing Wheel x3

All others are x1

Old One’s Army Scailing

In order to prevent a frustrating fight, some enemies are fixed at a specific number of players and will not be scaled based on how many actual players there are:

  • All Old One’s Army mobs at 5 players.

Exept for Bosses that have a different formula:

  • Betsy: 4 + (Active Players / 3)
  • Ogre: 3 + (Active Players / 3)

Super Enraged Wall of Flesh

When enabled the WoF is scaled to x20 base strength (time based scaling still applies) and health is reduced to 2.5% of what the health would be at that strength normally.

Boss AI Modifications

Queen Bee

Queen Bee has been modified to automatically despawn once it tracks a target that is no longer in a jungle biome or if Queen Bee is close to spawn, it’s likely the boss will still travel outside of any jungle biome but it should despawn once arriving at a player that is not within a jungle biome (be aware that jungle farms at spawn can still count as a jungle biome)


Plantera has been modified to automatically despawn once it gets close to spawn.

More Travelling Merchant Chances

Each day, a Travelling Merchant has 50% chance to spawn at 12:00 AM. Keep in mind it’s impossible to have two of it in the world and they follow the same restriction as a natural one to spawn.