Prerequisites: Dexterity 17
When you hit a creature with a melee weapon attack, you can expend a Maneuver Die to strike as to inflict crippling pain and force the creature to make a Constitution saving throw.
On a failure, its speed is halved; it has disadvantage on all attack rolls, ability checks, and saving throws; and to cast a spell it must first succeed on a Constitution saving throw or its spell slot (or use of that feature) is wasted.
This effect lasts for 1 minute, but the creature can make a Constitution saving throw without disadvantage at the end of each of its turns, ending this effect on a success.