Regaining hit points
A PC or follower regains HP when...
- … they Recover;
- … they Make Camp, and choose to regain HP;
- … they're at Death's Door and roll a 10+;
- … they have a few days of downtime and Convalesce;
- … another move says that they do; or
- … you offer them an opportunity to regain HP and they take it.
Non-follower NPCs and monsters regain HP when you decide that they do. Use the player moves as guidelines: a few minutes of rest and access to supplies will restore 3-5 HP; a night's rest will restore HP equal to half their maximum; a few days of rest and recovery will restore them to full HP. The fiction, of course, takes precedence. A supernaturally tough and resilient creature might restore its HP more quickly; a magical construct might not regain HP unless someone or something repairs or recharges it.
Remember, HP aren't "meat points." Regaining HP doesn't mean that wounds have closed or bones have knitted; it means they've grown accustomed to the pain, gotten the bleeding to stop, caught their breath. The injuries are still there until they heal. It's just that the character has more fight back in them, and is once again further away from a lethal blow.