The unit-boosting Doctrine system has been revised a couple of times since it was introduced in September 2019. The latest overhaul as part of the Blood of the Empire release aims to make Doctrines easier to manage and units more versatile.
The changes to the Doctrine system are twofold. The first is that the side of the Unit Details screen where you’d select Doctrines now takes you to a seperate screen. It’s here that you’ll notice the second major change, as Doctrines must now be “activated” before they can be learnt. This allows you to select the types of Doctrines you want to use and switch between them quickly and easily without destroying them.
Go to the Barracks tab of your Unit screen (U) and select the unit you wish to augment. On the right of the Unit Details screen (above), you will see all the Doctrines that are active and applied to the unit - up to a maximum of five. Just click in the area of the symbol to go to the unit’s Doctrine screen.
As on the previous unit screen, you can see which Doctrine slots are filled or empty. In addition, via the smaller icons you can see all the Doctrine types that can be understood by the selected unit. Those that are greyed out must be “activated” before they can be learnt. To do this, click on the slot you wish to fill, then the Doctrine you wish you activate from your Inventory. Hold down the mouse button to Activate, then you can select the Doctrine to have your unit learn it.
The purpose of activating a Doctrine for a unit before it can be learnt is so players can benefit from a broader selection of bonuses; by being able to switch types without losing any Doctrines in the process.
To return an active Doctrine to your inventory, click on its icon and select “Remove Doctrine”. This deactivation process will cost 1x Lotus Wine - a new item that can be acquired from the Seasonal Store (F5). No Doctrines are lost in the removal/deactivation process. You can also right-click on a learnt Doctrine to apply a new one without deactivating it.