The Elder Scrolls: Tamriel

When you hit a creature with a melee attack, you may spend 1 Focus to attempt a stunning strike. The target must succeed on a Constitution saving throw (DC = 8 + your Proficiency + your DEX modifier) or become Stunned until the end of your next turn. If the target succeeds the save, they suffer disadvantage on their next attack roll. At level 15, targets who fail are also slowed, halving their movement speed until the end of your next turn.