Stamina Points
Stamina Points represent the ability to turn a serious blow into a less serious one or to shrug off some attacks through sheer toughness. They act as a buffer that absorbs damage before it starts to deplete your Hit Points. When you take damage, you lose Stamina Points first, then you subtract any leftover damage from your Hit Points. If a creature doesn’t have Stamina Points, damage is subtracted directly from its Hit Points.
Source
Core Rulebook pg. 250
