In Gears of War 3 for the Xbox 360, you can unlock the Enemy Regen mutator, which will make non-lambent enemies regenerate health over time, and boost your experience gained by 10%.
To unlock the Enemy Regen mutator, you need to earn the Silver Aficionado medal by playing 150 chapters in Arcade mode.
Check out my other guide if you’re looking for the full list of unlockable mutators in Gears of War 3.
