You may want to try
Battle for Wesnoth. It is a single player computer game, with a strong theme, it is strategy based so it has some analysis, but is nowhere near the amount of analysis required for Dominions 2 (I would put it down at the level of hearts or cribbage). And it is free! It is a nice little war game with units representing individual soldiers, who get better as they fight through the campaign (if you can avoid getting them killed that is).
Teal