Naval warfare is the competition of sea-going power between nations at war. While a majority of warfare is land-based, the naval aspect of conflict can be incredibly influential in the spheres of trade and conquest.
In Imperator there are six different types of naval unit.
The main purpose of a fleet is to ferry troops from one destination to another, and to stop others from doing the same in your territorial waters. One ship can transport one cohort (with fully reinforced cohorts 1000 men). Fleets can also blockade ports in wartime, decreasing commerce and potentially contributing to the warscore for their side of the conflict. Futhermore fleets in a sea zone with a strait will block enemy units from crossing that strait.
Building a fleet
Ships can only be built in ports, which only exist in predefined locations around the map. Building ships other than Liburnians and Triremes also requires access to wood in the province that the city belongs to.
Combat is very similar to land warfare. The major differences are:
- Strength damage is higher than with land combat so ships more likely to sink in combat.
- Defeated ships have a chance to get captured.
As with land combat, navies have combat tactics that give bonuses against specific other tactics. How effective a tactic is depends on the fleet's composition.
Ships have a chance to be captured when they are defeated. There are 3 different cases:
- Morale runs out: This is the normal scenario. The capture chance is based on ship categories and the enemy general.
- Strength runs out: Same thing as above. However the ship gets destroyed even if it gets captured (resulting in multiple losses in the after battle screen).
- Stack wipe: Result of enemy being greatly outnumbered or getting defeated very quickly. The capture chance from the ship category is replaced by a fixed chance. Any captured ships during combat from the stack wiped side are returned to their original owners.
Sources of capture chance (all sources stack additively):
|Base||+6%||The global capture chance. Military window shows that the base chance is 5%. In-game tests resulted also in a hidden 1% base chance.|
|Stack wipe||+20%||Stack wiping doesn't involve combat so enemy ship category can't be used. In-game tests resulted in a 20% increased capture chance.|
|Capturing ship category||+10% per category||Capture chance is increased 10% for light ships, 20% for medium ships and 30% for heavy ships.|
|Captured ship category||−10% per category||Capture chance is decreased 10% against light ships, 20% against medium ships and 30% against heavy ships.|
|General martial||+0.2% * martial||Martial skill of the general slightly increases the capture chance. For example 10 Martial gives a 2% increased chance.|
|General trait Sea Dog||+10%||Sea Dog trait increases the capture chance.|
|Boarding Tactics||+10%||Selecting the Boarding Tactics ability increases capture chance at the cost of reduced damage.|
- Light vs Light, with level 10 martial. 6% + 10% - 10% + 0.2% * 10 = 8% capture chance.
- Light vs Medium, with level 10 martial. 6% + 10% - 20% + 0.2% * 10 = -2% capture chance.
- Medium vs Heavy, with Boarding Tactics. 6% + 20% - 30% + 10% = 6% capture chance.
- Heavy vs Heavy, with stack wipe. 6% + 20% - 30% = -4% capture chance.
- Light vs Heavy, with stack wipe and Boarding Tactics. 6% + 20% - 30% + 10% = 6% capture chance
There are unit abilities for ships at sea:
- Ramming Tactics: Naval damage done +10%, Naval damage taken +10%
- Boarding Tactics: Naval damage done -10%, Naval capture chance +10%
- Raid Port: Steals a number of pops from an adjacent port and turns them into Slaves in your capital (at a cost of 1 Aggressive Expansion).