Stamina pool is 1000. Sprint costs 100 per second. Regen out of sprint is 20 per second. The bar sits in the lower-left corner.
Several abilities spend stamina directly: Duelist dash — 400, Slasher dash — 100, Inquisitor Silence — 1000. If you don’t have enough, the game shows “Not enough endurance”.
The Endurance stat scales stamina efficiency through the shared attribute formula.