Hit points

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. A second source of Temporary Hit Points will overwrite the first if the second gives more Temporary Hit Points than the first source's initial value, regardless of how much of that initial value remains.^{[Needs Verification]}

Example: Level 1 Heroism applies 5 Temporary Hit Points when cast, and again each turn until it expires; and Level 1 False Life gives a one-time 7 Temporary Hit Points. If you have Heroism on you, and then you use False Life, you will have 7 Temporary Hit Points instead of 5. If you take 4 damage, you will have 4/7 Temporary Hit Points, but Heroism's 5 will still not overwrite that, neither through its per-turn applications, nor if you receive another casting of Heroism. However, if you lose that remaining 4/7 Temporary Hit Points, the next per-turn application of Heroism (if it's still active) will give you 5/5 Temporary Hit Points.

Taking damage to your Temporary Hit Points will still cause a Concentration check (when Concentrating), even if the damage doesn't overflow into your base Hit Points.

Temporary Hit Points do not remove Downed and disappear after a Long Rest.