What it does
Bad Breath is one of Magic's earliest "flavor" abilities, appearing on the card of the same name from the Legends set. It's an instant that reads "All creatures get -2/-1 until end of turn." It's not actually a keyword—just a one-off effect with a memorable name—so there's no rules template attached to it.
The nuance: the -1 toughness can kill X/1 creatures across the entire board, including your own. It hits all creatures, not just opponents', so it's symmetrical. Creatures with toughness reduced to 0 are put into the graveyard as a state-based action; this isn't damage, so indestructible doesn't save a creature whose toughness drops to 0, but regeneration won't help either since nothing is "destroyed."
In Commander, it's a weak, nostalgic sweeper—mostly a collector's curiosity rather than a competitive include, given far better board wipes exist.
Iconic cards with Bad Breath
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