A single massive hit can cause trauma that HP alone doesn’t represent: shattered bones, ruptured organs, catastrophic blood loss, and it takes a massive toll on the body regardless if you immediately feel its effects or not.
Optional Rule: Lingering Injury, pg 272 of the DMG
The Rule
If a creature is dealt a single instance of damage that equals or exceeds 50% of a creature’s hit point maximum, it gains levels of exhaustion based on severity:
| Damage (% of Max HP, single hit) | Exhaustion Levels Gained |
|---|---|
| Under 50% | None |
| 50% | 1 |
| 75% | 2 |
| 100% | 3 |
| 125% | 4 |
| 150% | 5 |
| 200% or more | 6 — instant death |
Use hit point maximum, not current HP so the severity is consistent.
Single Instance Damage
All damage from the same attack or effect counts as one instance, including added damage such as Divine Smite or elemental weapon damage.
- Damage requiring a separate roll or saving throw is a separate instance.
- Multiple attacks are checked individually.
Damage Reduction
Catastrophic Damage is based on the final damage that reaches the creature, after applicable damage reduction, resistance, or mitigation.
- Creatures abilities, traits, armor, enchantments or other reduce both damage taken and the severity of catastrophic trauma to the body.
- Temporary HP does not reduce the damage used for the Catastrophic Damage check. Its instead based off your maximum hit point threshold.
NOTE: This is experimental and can be subject to change depending on play and player preferences.
