Exhaustion reduces the character's maximum energy. When exhaustion occurs, the caster loses 10 maximum energy. The amount of maximum energy lost is shown at the right end of the energy bar (in its default position) as greyed out. Maximum energy is recovered at a rate of 1 point of energy every 3 seconds. Exhaustion stacks. A character repeatedly casting exhaustion spells will repeatedly reduce their maximum energy, lower and lower each time. Exhaustion can lower maximum energy below zero. In this case, the deficit is regained at 1 point per 3 seconds before regaining positive maximum energy.