Following the recent Japanese explanation for the weapon triangle in Fire Emblem Engage and the game’s Break mechanics, for those who were waiting for Nintendo to provide an English explanation on the matter, Nintendo of America has just recently taken to Twitter and provided the following:
In #FireEmblem Engage, each character wields various weapons and certain weapons have advantage or disadvantage against other types of weapons. Swords > Axes Axes > Lances Lances > Swords Also, arts have advantage over bows, tomes and knives.
In #FireEmblem Engage, you can inflict the break status on an enemy by landing an attack with a weapon that has advantage. Broken units cannot counterattack until after their next attack, so you can use it to gain the advantage in battle.
Other tweeted tidbits from the American branch also include videos of exchanges between Male Alear with Marth and Female Alear with Celica.