Hold Breath (Proficiency)

Hold Breath: This proficiency helps a character hold her breath for extended periods of time. (See the rules in the Player's Handbook, Chapter 14, for the amount of time a character can normally hold her breath.)
With Hold Breath proficiency, a character can hold her breath for half her Constitution score in rounds (rounded up). If the character is exerting herself, this time is halved (again rounding up). When attempting to hold her breath beyond this time, the character rolls the usual
Constitution check each round. The first check has no penalty, but each subsequent check takes a cumulative –1 penalty. Once a check is failed, the character must breathe; if she cannot reach air, she dies.
Category:The Complete Ninja's Handbook Proficiencies