Undercity Uprising is a common Sorcery card from Guilds of Ravnica (GRN), collector number 210. Current market price: $0.24 (foil $0.35), TCGplayer market prices via Scryfall.
Creatures you control gain deathtouch until end of turn. Then target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)