Protection
With a shield, Protection can impose disadvantage on an enemy attacking a nearby ally when the Fighter can see that enemy.
How it works
Protection is a level-one Fighter Fighting Style choice. It requires a shield and an enemy attacking one of the Fighter's allies while the Fighter is within 1.5 m (5 ft). The Fighter must be able to see the enemy; under those conditions, the enemy has disadvantage on the attack roll.
Read the supporting references
Selected Fighter fighting styles and Battle Master progression, Warlock invocations and Pact Boons, and Ranger Favoured Enemy and Natural Explorer choices. Effects and explicit conditions are drawn from the supplied passages; comparative effectiveness is not assessed. Guidance explains the referenced mechanics; it is not a tested damage ranking. Check the stated edition and source version before applying a patch-specific detail.