Armies are collections of troop units. The number of units in any given army may range from one to as many as you can afford to maintain. Each kingdom is allowed to have one provincial army for each province in its empire, and a minimum of two imperial armies. Each kingdom has one imperial army for every three provinces it controls. (The computer will round up; if you control eleven provinces, you will have four imperial armies.) An army may hold up to 30 troop units at once under normal circumstances. Imperial and provincial armies operate differently in defense, raid, or invasion situations. These three situations are covered separately later in this section.