Speed/Resistance Solo (Japanese: 速さ魔防の孤軍Speed/Resistance Lone Force) is a three-tiered passive type A skill which debuted in Fire Emblem Heroes; the individual tiers of the skill are known as Spd/Res Solo 1, Spd/Res Solo 2, and Spd/Res Solo 3 in order from lowest to highest. Units with a Spd/Res Solo skill boost their Speed and Resistance during combat provided they do not have an adjacent ally; the size of the Speed and Resistance boosts are affected by the skill's tier.