Mechanics for Naval Combat

Every fleet has a certain amount of cohesion, representing the tonnage that fleet holds. For humans, this is 6/6, but if it is a house retinue, elite mercenaries, an armada's flagship, or holding the Emperor, it gains +2 for each bonus that applies.

In combat, fleets roll against each other and the amount the higher exceeds the lower roll is applied as damage. For humans, a 1d6 is rolled, but if it's a naval fleet (as opposed to pirates or militia), a house retinue, an armada's flagship, or holding the Emperor, it gains +1 for each bonus that applies.
Certain bonuses may apply to cohesion or roll on a situational basis. If a fleet reaches 0 or less cohesion, it's destroyed and the admiral leading it is killed in battle. If the Emperor is slain, it will impact the wider Empire.

Every round, each fleet must engage an enemy fleet or be held in reserve. Every fleet engaging the same enemy fleet past the first gains a +1 bonus. For example, three fleets engaging the same enemy would gain a +2 bonus.

A fleet may choose not to engage and withdraw instead. If a withdrawing fleet is engaged, if it wins, it doesn't damage the enemy fleet but flees. If it loses, it's damaged and stays for the next round. If a fleet flees, it leaves the campaign but survives for the future. If a fleet isn't engaged by the enemy and withdraws, it automatically flees.

There are three strategies a fleet must choose between when engaging in combat. These are: Charge, Feint, Defend.

Charge counters Feint, Feint counters Defend, Defend counters Charge.

If a fleet chooses a strategy that counters its enemy, it gains a +2 bonus to its roll.

If a fleet chooses the same strategy as its enemy, both fleets suffer halved damage.

If a fleet chooses a different strategy, the rolls are read as normal.

If multiple fleets are engaging the same enemy, every fleet that the enemy isn’t targeting receives halved damage from losses, while if fleets have the same strategy as the enemy, they suffer none.