Hit Points (or HP) is a number representing a creature's life force, or an object's structural integrity. It indicates how much damage you or party members can take before being Downed, and how much damage creatures and items can take before being killed or destroyed.
Taking damage affects how injured your character appears, with more cuts and bruises appearing as HP percentage drops.
The amount of hit points of a player character is determined by their Class + 
Constitution modifier.
- Barbarians start with 12 HP and gain +7 with every level up.
- Fighters, Paladins and Rangers start with 10 HP and gain +6 with every level up.
- Bards, Clerics, Druids, Monks, Rogues and Warlocks start with 8 HP and gain +5 with every level up.
- Sorcerers and Wizards start with 6 HP and gain +4 with every level up.
Temporary Hit Points
Temporary Hit Points are additional Hit Points that are lost before your base Hit Points.
You can only have one set of Temporary Hit Points at a time, and healing can't restore them. Temporary Hit Points do not remove Downed and disappear after a Long Rest.