This is a Barbarian class feature.
- Your rage can keep you fighting despite grievous wounds. If you drop to 0 hit points while you're raging and don't die outright, you can make a DL 10 Fortitude save. If you succeed, you drop to 1 hit point instead.
- Each time you use this feature after the first, the DL increases by 5. When you finish a short or long rest, the DL resets to 10.