Stamina

While magic deals with complex formulae, precise manipulation of components, and intense concentration, martial acumen often relies on seizing opportunities and pushing the body and the will to carve a path to victory on the battlefield. Those who make their way in the world by skill at arms know that the determination to test the limits of endurance often separates the living from the dead and the vanquished from the victorious.
Stamina and Combat Tricks help characters better reflect this opportunistic flexibility and the give-and-take of the battlefield. This system allows a character to draw upon an internal reservoir of will and gumption to overturn the assumed limitations of combat, at least for short bursts. With luck and proper timing, a character using this system can snatch victory from the jaws of defeat or put a despicable villain to a stunning end.
You can spend Stamina to perform any Combat Tricks you have access to.
Dropping to 0 stamina points causes you to become Fatigued until you have 1 or more points in your stamina pool.
Temporary increases to your Constitution score, such as those granted by Bear's Endurance, do not increase the number of stamina points in your pool or your pool’s maximum number of stamina points. However, permanent increases to Constitution, such as the bonus granted by a belt of mighty constitution worn for more than 24 hours, do adjust your stamina points.
You regain stamina points through short or long rests. When taking a short rest, you recover a number of stamina points equal your Constitution modifier (minimum 1). A fighter can also spend fighter dice to recover stamina (see the Resting article). All characters replenish their entire stamina pool after a long rest.