Hit Dice

Each creature has a number of Hit Point Dice, usually called Hit Dice or HD. For an NPC these are listed in its stat block, in parenthesis next to its hit points. Hit points represent shorter-term resilience against damage, while Hit Dice represent longer-term resilience against exhaustion.

As a protag, the number and size of your Hit Dice are usually determined by your class. Even if you lack a class you always have at least one Hit Die, which is a d8 if you're Medium or d6 if you're Small.

Expending Hit Dice. You can willingly expend Hit Dice during a break to recover more hit points, and some features enable you to expend Hit Dice for other benefits.

Exhausting Hit Dice. An extreme climate or other hazard can force you to lose Hit Dice. If you are forced to lose one or more Hit Dice when you have none remaining, roll your largest Hit Die and reduce your hit point maximum by an amount equal to the result.

Restoring Hit Dice. When you finish camping, regain a number of Hit Dice equal to your Constitution (but not less than 1). When you finish Downtime, regain all Hit Dice.