What are unit doctrines

Doctrines are special modifiers you add to a unit to improve its stats and abilities: more damage, better defense, faster cooldowns and so on. Each unit has five doctrine slots, and doctrines come in rarities (Uncommon, Rare, Epic and up) with levels I to V once Epic.

The most common way to get them is excavation with treatises via the X menu. You can also use the Doctrine Alchemy system. Equip them through your U menu. Some doctrines are specific to unit types (ranged, melee, crossbow, archer, lance cav, sword cav), which you can see by hovering the unit, and some are unique to a single unit.

Choosing the right ones matters a lot, follow the recommended doctrines in each unit's guide. For what every doctrine does and which units can slot it, see the Doctrines page.