A long rest is a period of extended downtime, at least 8 hours long, during which a character sleeps or performs light activity: reading, talking, eating, or standing watch for no more than 2 hours. If the rest is interrupted by a period of strenuous activity—at least 1 hour of walking, fighting, casting spells or similar adventuring activity—the characters must begin the rest again to gain any benefit from it.
- The character regains Hit Points equal to their Constitution modifier (minimum 1) multiplied by their level. If they rest without any shelter or comfort, you might reduce this healing by half (to a minimum of 1 HP).
- The character also regains spent Hit Dice up to a number of dice equal to half of the character’s total number of them (minimum of one die).
- Most spellcasters need to rest before they regain their spells for the day.