A cover force partially denies the use of a city to the enemy, and preserves a siege but cannot advance it. A city is covered automatically whenever there is a sufficient number of non-moving troops in a province with an enemy-controlled city.
Requirements to Cover
To cover a city, it must be enemy-controlled, and there must be enough non-moving friendly troops present. The amount required is 1000 troop-equivalents per level of the fortifications.
Fort level Number required to cover 1 1000 2 2000 3 3000 4 4000 5 5000 6 6000
Required troop amounts are computed in equivalents, where one cannon is equivalent to 100 men. For example, a force of 2000 infantry and 30 cannon is sufficient to cover a level 5 fort.
Effects of Cover
When a city is covered, the following effects hold:
- The city cannot initiate new troop recruitment. It can complete already-ordered troops.
- Siege progress is not reset at the end of the month.
- the country owning the covering army can trace supply lines through the province.
In addition, if a siege force is reduced to a cover force but never "uncovers" the city at any time, the siege progress day will be kept and the cover force will get one more siege progress attempt before the siege is suspended. This means sometimes a cover force will succeed in capturing a city. It also makes possible the tactic of "bouncing".
The Cover Button
When the player has selected a stationary army at a siege that is more than 20% larger than the amount required to cover the city, the "cover" button will be active. Pressing it will split the army, creating a new army of the size required to cover plus 20%. At a siege of a minimum fort, for example, 1200 men is the magic amount: when an army has at least that many, you can select it and press "cover", splitting the army into a new 1200 man force, and the rest.