Imperial doctrine determines the strategic focus of an empire. Additional doctrines are present in the game code but are not implemented. Doctrine switching is performed from the Empire tab on the Imperial Capital. Switching doctrine will temporarily depress efficiency on the imperial capital and sector capitals because it causes these planets to be redesignated. If any empire has >100 planets and >2 sector capitals, sector capitals can randomly secede; this is essentially unavoidable except for players in the Law & Order doctrine.

Jumpship-focused doctrine. Imperial and sector capitals get the Fleet HQ primary structure, which builds TL-appropriate jumpships plus basic infantry. They also get a jumpship autofac structure that will activate as needed, allowing the capital to build any jumpship without requiring a designated jumpship components autofac world. The Fleet HQ structure includes a jump beacon, similar to jumpship yards. This allows jumpfleets to move to planets within 250LY of the sector capital. This is the default doctrine of the NPC “Warlord” empires present at game start and of secession empires that form as a result of sector capitals seceding.

Starship-focused doctrine. Imperial and sector capitals get the Starship HQ primary structure, which builds TL-appropriate starships plus basic infantry. They also get a starship autofac structure that will activate as needed, allowing the capital to build any starship without requiring a designated starship components autofac world. The imperial capital must not be in a nebula to switch to this doctrine. Sector capitals in nebulas still build starships, but the starships will not be movable.

Mesophon-purchase-centric doctrine. Imperial sector capitals get the starport primary structure, which causes the world to function as a trading hub and does not require labor. They also get the militia base structure, which builds basic infantry. Capitals and hubs can form one-way trade routes with Mesophon worlds to sell any resource. The militia base will permanently disappear if it is ever receiving 0% labor; this is a bug. This is the doctrine of the NPC Mesophon Traders Guild empire. This doctrine can be difficult to leave because the trade hub ability of capitals stops working when a new doctrine is adopted. If the capitals are being used as hubs, the imperial economy will instantly collapse.

Growth-centric doctrine for large empires. Imperial sector capitals get the Imperial Security primary structure, which builds Imperial Guards units. Random secession appears to be only 10% as common under this doctrine by default. The presence of Imperial Guards on sector capitals further decreases the risk of secession, rendering it effectively impossible as long as more than a few of these units are present. A L&O empire will has no real size limit as long as Imperial Guards are being built. Worlds with Imperial Guards are less likely to revolt and Imperial Guards will never join rebels.

This doctrine exists in the game code but is not implemented.

This doctrine exists in the game code but is not implemented.