Asthmatic

Harsh conditions or long exertions overtire you and set you to wheezing. You suffer the following penalties:

• You have disadvantage on exhaustion checks imposed while travelling.
• You may only use the dash action once per turn, even if a spell or feat (such as the rogue's cunning action, or Expeditious Retreat) allows you to use it twice.
• You have disadvantage on any saving throws against effects caused by cloud, dust, fog, or smoke.
• You can hold your breath for only half the normal duration.
  • You can hold your breath for a number of minutes equal to (1 + your Constitution modifier) / 2 minutes (minimum 15 seconds).
  • When you run out of breath or are choking, you can survive for a number of rounds equal to half your Constitution modifier (minimum of 1 round).

  • For example, with a Constitution of 14, you can hold your breath for 1.5 minutes. If you start suffocating, you have 1 round to reach air before you drop to 0 hit points.

FLAW. This is a flaw feat. At your DM's discretion, you may take this feat at level 1. If you do, you may also gain a feat, or increase two of ability scores by +1 (or one by +2).