Which Fire Emblem game first introduced the Weapon Triangle?

Fire Emblem: Genealogy of the Holy War was the first Fire Emblem game to introduce the Weapon Triangle. The system gives swords, lances, and axes a rock-paper-scissors relationship in battle.

Under the original triangle, swords have an advantage over axes, axes have an advantage over lances, and lances have an advantage over swords. The matchup affects combat effectiveness, helping players decide which units should engage one another. This added another layer of tactical planning to the series' grid-based battles.

Genealogy of the Holy War was released for the Super Famicom in Japan in 1996. It is set on the continent of Jugdral and follows two generations of characters, beginning with Sigurd and later shifting to his son Seliph. Its large maps, inheritance system, castles, and generational storyline already made it one of the series' most structurally ambitious games.

The Weapon Triangle later became one of Fire Emblem's best-known mechanics, although its exact rules and availability have varied between games. It should not be confused with the “triangle attacks” performed by certain groups of units, which are a separate mechanic.