Fire Emblem Heroes weapon Mt stat not added to damage?
Solution 1:
The Attack stat already includes the weapon's Might
Unlike most Fire Emblem games, Heroes does not have dedicated Strength and/or Magic stats. Instead, it has a single Attack stat that covers both physical and magic damage. However, it also already includes the Might of your currently-equipped weapon. If you go into the Equip Skills menu and change a unit's currently-equipped weapon, you'll see their Attack stat also change accordingly (you don't need to confirm the weapon change, the stats will update immediately).
Therefore, when calculating damage, don't add your weapon's Might to your Attack stat, because it has already been added.