Which Fire Emblem game was the first to support Amiibo functionality?

Fire Emblem Fates was the first Fire Emblem game to support Amiibo functionality.

Released for Nintendo 3DS in 2015, Fates lets players scan compatible Fire Emblem Amiibo, including Marth, Ike, Robin, and Lucina. These scans can make the characters appear in the player's castle and unlock special interactions and gameplay rewards.

The timing is important: Fire Emblem Awakening came earlier, in 2012, but it did not offer the same kind of in-game Amiibo support. Fire Emblem Echoes: Shadows of Valentia added Amiibo functionality later, while Three Houses followed on Nintendo Switch in 2019.

Fates is also notable because its three story routes—Birthright, Conquest, and Revelation—were sold through separate versions or downloadable content. Amiibo support is therefore an extra feature associated with the 3DS generation of the series, not a feature present in every earlier Fire Emblem title.