Constitution Checks

Constitution checks are uncommon, and no skills apply to Constitution checks, because the endurance this ability represents is largely passive rather than involving a specific effort on the part of a character or monster. A Constitution check can model your attempt to push beyond normal limits, however.
The GM might call for a Constitution check when you try to accomplish tasks like the following:

• Hold your breath

• March or labor for hours without rest

• Go without sleep

• Survive without food or water

• Quaff an entire stein of ale in one go