Attack/Resistance Oath is a three-tiered passive type C skill which debuted in Fire Emblem Heroes; the individual tiers of the skill are known as Atk/Res Oath 1, Atk/Res Oath 2 and Atk/Res Oath 3 in order from lowest to highest. Units with an Atk/Res Oath skill will, if the user is adjacent to any allies at the start of their phase, boost the user's Attack and Resistance for the duration of the turn; the Attack and Resistance boosts increase with the skill's tier.