Accorder's Shield is a uncommon Artifact — Equipment card from Magic 2014 (M14), collector number 204. Current market price: $0.18 (foil $1.03), TCGplayer market prices via Scryfall.
Equipped creature gets +0/+3 and has vigilance. (Attacking doesn't cause it to tap.) Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)