Suffocation

HazardXPHBp. 3762024

A creature can hold its breath for a number of minutes equal to 1 plus its Constitution modifier (minimum of 30 seconds) before suffocation begins. When a creature runs out of breath or is choking, it gains 1 Exhaustion level at the end of each of its turns. When a creature can breathe again, it removes all levels of Exhaustion it gained from suffocating.

Raw data

{
  "name": "Suffocation",
  "page": 376,
  "__prop": "hazard",
  "source": "XPHB",
  "entries": [
    "A creature can hold its breath for a number of minutes equal to 1 plus its Constitution modifier (minimum of 30 seconds) before suffocation begins. When a creature runs out of breath or is choking, it gains 1 {@condition Exhaustion|XPHB} level at the end of each of its turns. When a creature can breathe again, it removes all levels of {@condition Exhaustion|XPHB} it gained from suffocating."
  ]
}