Cheapest priced copy (Secrets of Strixhaven Mystical Archive): $0.35 at Card Kingdom, near mint, their price list as of .
Knockout Maneuver 
Sorcery · Uncommon · Tarkir: Dragonstorm · #147
Put a +1/+1 counter on target creature you control, then it deals damage equal to its power to target creature an opponent controls.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
4 printings · $0.35 to $3.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Secrets of Strixhaven Mystical Archive | 54 | Uncommon | $0.35 | $0.49 |
| Secrets of Strixhaven Mystical Archive | 119 | Uncommon | $0.35 | — |
| Secrets of Strixhaven Mystical Archive | 184 | Uncommon | — | $3.99 |
| Tarkir: Dragonstorm | 147 | Uncommon | $0.35 | $0.49 |
2 rulings from Wizards of the Coast
- 4 April 2025You can't cast Knockout Maneuver unless you choose a creature you control and a creature an opponent controls as targets.
- 4 April 2025If either creature is an illegal target as Knockout Maneuver resolves, the creature you control won't deal damage. If the creature you control is an illegal target, you won't put a +1/+1 counter on it even if it's still on the battlefield.