Mutiny

In Commander, Mutiny earns its slot in red decks that can't otherwise touch indestructible or hexproof creatures through combat — forcing a fight bypasses protection that targeted removal can't crack, and for one mana it's hard to argue with. The catch is that it requires your opponent to control a creature large enough to kill what you're aiming at, which in a four-player game is usually a safe assumption. In Pauper it's a legitimate one-mana interaction piece with real competitive applications in aggressive red builds. Legacy, Modern, and Pioneer have access to better and more consistent removal options, so Mutiny sits on the fringe there — playable in budget builds but rarely the correct choice.