Protection

D&D 2014 optional feature: Protection. Source: Player's Handbook (2014). feature type Fighting Style, FS:P When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield. Fighting Style, FS:P

Source: Player's Handbook (2014), p. 72 - Licenses and attribution