Burnout is a mechanic of Ars Magica 2 which stops mages from using spells at an infinite rate, basically giving spells a 'fire rate'. Burnout is represented by a red bar and is an indication of your magical fatigue. Your maximum burnout increases by magic level. Burnout increases the mana cost of spells by a percentage, and slowly is reduced over time. Spells that take more mana to cast increase burnout by a greater amount. Some armor imbuements can be made to decrease burnout rate, there is currently no way to 'deactivate' burnout or edit it through the configs though.