Taking the role of Byleth, a former mercenary with a mysterious past and the academy's newest professor, the player must choose a class to lead and guide their students through a series of battles.

The game maintains the turn-based tactical gameplay of the previous Fire Emblem titles, while incorporating social simulation and time management elements.

The game's production was challenging for Intelligent Systems, who attributed its success and timely release to Koei Tecmo, who had previously partnered with the company for Fire Emblem Warriors.

The staff wanted something entirely new for the franchise's debut on high-definition home consoles, birthing the school life mechanics and expansions to battle.

The game's school system and a time skip later in the story took inspiration from the fourth installment, Fire Emblem: Genealogy of the Holy War.

The game received generally favorable reviews, with critics praising the integration of the school system and battalion mechanics, narrative, characters, soundtrack, and replay value.

[1] The player's time is divided between story-based battles that advance the main narrative, and periods in Garreg Mach where they interact with students and staff members there.

[3] During the periods between storyline battles, the player has a set number of days marked on a calendar, which can be used for a variety of activities from teaching classes and field exercises to planting seeds in the greenhouse and fishing in the pond.

[6] As with other Fire Emblem games, Three Houses uses a turn-based battle system; players take control of a set number of unique units.

[2][3] Prior to starting a school week, lesson plans can be put into place to individually manage a unit's growth, build Support between two classmates by engaging them in group assignments, or simply instruct the class automatically with a passive "auto-instruct" feature.

Rather than the previously established Weapon Triangle of earlier Fire Emblem games, different units have weapon-based skills called Combat Arts they can be taught during the school segments.

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.

Jeralt reluctantly rejoins the Church's military arm, the Knights of Seiros, while Byleth is made a professor of the monastery's Officers Academy.

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.

A magical attack by one of their leaders forces Sothis to merge with Byleth, allowing them to survive and defeat the cult members with a newly empowered Sword of the Creator.

Aelfric theorizes that the mercenaries are looking for the Chalice of Beginnings, a key object in a ritual attempted during Garreg Mach's early days with the aim of resurrecting Sothis.

Aelfric is revealed to be the mastermind, capturing the Ashen Wolves and preparing to use the Chalice to resurrect Byleth's mother Sitri, for whom he held a secret love.

After consultation, Koei Tecmo's internal team led by Kou Shibusawa and responsible for the tactical series Nobunaga's Ambition was recommended to them.

[13] Full production began in 2017 when Shadows of Valentia was finished, with Toshiyuki Kusakihara and Genki Yokota—respective directors for Intelligent Systems and Nintendo EPD— returning to direct the game.

All three previously worked on the scenario for Warriors and were brought onto the development of Three Houses to help assist Intelligent Systems in writing the social segments of the game.

[10] The first storyline conceived was the Black Eagle House, with Kusakihara and the other scenario writers building and expanding on the world and characters from that starting point.

[13] Kusakihara also admitted influence from the Chinese novel Romance of the Three Kingdoms and Koei Tecmo's adaptation of it in the Dynasty Warriors game series; this came about after Intelligent Systems looked at the narrative and world designs used by the Kou Shibusawa unit.

[11] Kurahana was in talks with Intelligent Systems prior to development, and the final decision was made as Kusakihara felt she could best illustrate the "glamorous, aristocratic society" portrayed in the game.

[12] The team toyed with the idea of including child characters from romantic supports for the story's second half, a feature from Genealogy of the Holy War which they had used extensively in Awakening and Fates.

[34] Aron Garst of GamesRadar gave Three Houses a perfect score, praising how the game kept him invested in its characters, with his main criticism of the gameplay being its low difficulty.

[36] Brendan Graeber of IGN felt that its depth of characters and tactical options more than justified multiple playthroughs, particularly praising its narrative as being superior to that of Fire Emblem Fates.

[39] The scenario was met with praise, being cited as a mature and ambitious narrative with strong character interactions, with many lauding the difficult choices presented when picking a side in the first half of the campaign.

[46] In August 2019, the NPD Group shared the ranking of best-selling games for the month of July in the United States, and Fire Emblem: Three Houses was in second place counting only physical sales.

It is set in the same universe as Fire Emblem: Three Houses along with the same cast of characters, but features an alternative story where Byleth does not come to teach at the monastery, along with a completely new protagonist and scenarios.