Savage Offensive is a common Sorcery card from Invasion (INV), collector number 162. Current market price: $0.08 (foil $0.47), TCGplayer market prices via Scryfall.
Kicker {G} (You may pay an additional {G} as you cast this spell.) Creatures you control gain first strike until end of turn. If this spell was kicked, they get +1/+1 until end of turn.