It is per server, so anyone logged in to that server contributes to boss health scaling. This means having more players can potentially be detrimental if they are not actively contributing and carrying their weight towards boss damage. According to this thread.
Does multiplayer Terraria make bosses harder?
Do monsters and bosses getting stronger when 2 friends join my multiplayer game? Yes, boss health scales and invasion kills required scale, but only on expert mode.
Are bosses stronger in multiplayer Valheim?
The new patch for Valheim makes bosses harder and introduces a number of improvements to stability–and more. A new Valheim patch has toughened up a few of the multiplayer survival RPG’s boss enemies.
How does the difficulty scale with more players?
The health scales by 130 – 140% of the “one less player” health (ie. for three players it has ~135% the hp that it had for 2 players). If you’re looking for specific numbers for a boss you intend to summon, this thread is an excellent place to look.
How does multiplayer scaling affect the difficulty of Outriders?
One of the great joys in Outriders is shredding hordes of enemies using your guns, altered powers, and wits. While fighting is fun solo, it pales in comparison to playing with a full squad; multiplayer scaling has a direct and significant impact on difficulty, in more ways than one.
How does multiplayer health scaling work in Minecraft?
Your observations for Multiplayer health scaling is only on Expert Mode. Only health scales, not damage. Only boss health scales. Common enemies have static health (but double compared to normal mode) It is per server, so anyone logged in to that server contributes to boss health scaling.
How does difficulty scaling work in Monster Hunter rise?
Monster Hunter Rise’s multiplayer difficulty scaling is very fluid. This means, you can start a mission on your own and should a player/s join you, the monster will automatically scale up (or down should somebody leave).
