Mon Jan 04, 2010 6:27 pm
I'm relatively new to the game, but here is my best answer:
You can request "element reinforements" in the Military Options screen (click the globe on the UI and open page three) which the AI will release based on certain criteria. You can request militia, regular units, elite, indians, etc. I'm not exactly sure, but I believe units in larger cities, who haven't moved, etc will get priority. Again, these are just adding to the elemental units already in the field.
In other cases, you request actual units using the same Military Options screen. I have seen a request for regular units, Highlanders, seige cannon, dragoons, and naval units. These units are then placed in friendly ports and ready for action.
Finally, as the previous poster indicated, there are certain scripted events that occur where the player receives units immediately. For example, the English Fleet might sail into Halifax and you'll have ships of the line. You also have instances where the player will receive various militia throughout the empire.
"Good fortune is more fatal to princes than adversity: during the former they are intoxicated with presumption; the second renders them circumspect and modest." ~ Frederick the Great