Settings and synopsis

Three Houses takes place on the continent of Fódlan. The landmass is divided into three rival nations who are now at peace: the Adrestian Empire to the south and west, the Holy Kingdom of Faerghus to the north, and the Leicester Alliance to the east. The Church of Seiros, based at Garreg Mach Monastery at the continent's center, is the region's dominant religion and is an influential power in Fódlan in its own right. In ancient history, a war raged between the Church's titular founder Seiros and the "King of Liberation" Nemesis, an era which also saw the establishment of the Empire by Seiros. In the thousand years since then, the Kingdom split away from the Empire, then the Alliance declared its independence from both powers. A prolonged conflict ensued, with the Church being responsible for keeping peace. The nobility of Fódlan frequently bear Crests, sigils passed down through families that grant magical powers. Bearing a crest greatly influences dynastic politics, with nobles inheriting Crests valued far above those who lack them. Those who have Crests can also wield powerful artifacts called Hero's Relics. The series's titular "Fire Emblem" appears as the "Crest of Flames", the Crest associated with the Progenitor God.

Players take on the role of the main character, called Byleth by default and who can be either male or female. A mercenary by trade, they become enrolled in the Officers Academy of Garreg Mach Monastery as a teacher. During their journey Byleth is aided by Sothis, a strange and initially-amnesiac girl who appears in their dreams and can only be heard by them. At Garreg Mach Monastery, Byleth chooses one of the three school houses, each aligned to a different nation of Fódlan. They are the Black Eagles led by Edelgard von Hresvelg, imperial princess and heir to the Adrestian throne; the Blue Lions commanded by Dimitri Alexandre Blaiddyd, crown prince of the Kingdom; and the Golden Deer led by Claude von Riegan, heir to the Alliance's leading family. The Monastery's staff includes those who directly work for the Church, some of whom are recruitable by the player. Other characters include Jeralt, father of Byleth, and Rhea, archbishop of the Church.

Plot

One night, Byleth and Jeralt rescue three young nobles, Edelgard, Dimitri, and Claude from bandits, greatly impressing them. During the attack, Byleth is saved by the mysterious Sothis, who remains within them. Jeralt and Byleth are summoned to Garreg Mach Monastery, the home of the Church of Seiros, Fódlan's dominant religion. Jeralt reluctantly rejoins the Church's military arm, the Knights of Seiros, while Byleth is made a professor of the monastery's Officers Academy. Jeralt privately warns Byleth not to trust the Church's archbishop, Rhea. Byleth is then given the choice of leading one of the academy's three houses: the Black Eagles, the Blue Lions, or the Golden Deer, each populated by students from the Empire, Kingdom, and Alliance respectively. Byleth assumes their duties as teacher for their chosen house, training their students and leading them in battles on behalf of the Knights of Seiros. Byleth and their students discover frightening hints on the nature of Relics and Crests, such as a Relic thief transforming into a monster. Various conspiracies meddle with the monastery and plot against the Church: masked warriors called the Flame Emperor and the Death Knight, the Western branch of the Church, and a hostile cult known as "those who slither in the dark". Byleth thwarts an attempt to steal a powerful Hero's Relic, the Sword of the Creator. Unexpectedly, the Sword activates when Byleth holds it, and Rhea allows them to keep it.