Death Saving Throws

Roll a d20 at the start of each turn while at 0 hit points (no modifier)
- 10 or higher: success; 9 or lower: failure
- Natural 20: regain 1 hit point
- Natural 1: counts as two failures
- Any healing ends the process and brings you above 0 hp
  - Temporary hp don't count
3 successes: stabilised — no more checks (still at 0 hp)
- Unless healed, a stable creature regains 1 hp after 1d4 hours
3 failures: dead
Failures and successes are reset instantly when stable or healed
Taking damage adds a failure
- Taking a critical hit is 2 failures
- While unconscious, attacks have advantage, and attacks from within 5 feet are automatic criticals
- If you take more damage than your hit-point maximum, you automatically die
Make a DC 10 Medicine check to stabilise another creature

Player's Handbook, page 197, Player's Handbook, page 198