Allied Assault is a uncommon Instant card from Zendikar Rising (ZNR), collector number 1. Current market price: $0.10 (foil $0.36), TCGplayer market prices via Scryfall.
Up to two target creatures each get +X/+X until end of turn, where X is the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)