First appearing in Thracia 776, Fatigue is a mechanic that discourages relying on a (very) small group of units. Although it’s thankfully a lot, lot easier to work with in this game.

As a unit performs actions or receives damage, the unit’s invisible Fatigue meter gradually builds up.

Action Fatigue
Enter combat or use White Magic +1
Take 0 or 1 damage +1
Take 2 or more damage +2
Take damage from terrain +1

Once the unit’s Fatigue level is equal to their Maximum HP, their maximum HP will be temporarily reduced after the battle is over. The reduced HP is equal to the maximum HP multiplied by the unit’s Fatigue Tolerance.

For example, if Celica has 30 HP, she will have 18 HP when fatigued.

The current level of Fatigue can be determined by the face icon next to a unit’s HP.

Icon Fatigue Level
Less than 1/3 of Maximum HP
Over 1/3 of Maximum HP
Over 2/3 of Maximum HP
Equal to Maximum HP

Fatigue can be reduced by consuming Provisions. It can also be fully cleared by exiting to the world map, offering any Provision to a Mila Idol or after a Class Change. Therefore, during non-dungeon battles, Fatigue has no impact.