Sekigahara is a three-hour, low-complexity block wargame based on Tokugawa’s campaign in 1600 that would unify Japan for over 250 years.
The game features some unusual mechanisms:
No dice are used; combat is decided with cards. Blocks = armies & cards = motivation. The combination of army and motivation produces impact on the battlefield. Armies without matching cards don’t fight.
Legitimacy is represented by hand size, which fluctuates each week according to the number of castles a player holds.
The initial setup is variable, so the situation is always fresh. Concealed information (blocks and cards) lends additional uncertainty. In this way it ‘feels’ something like an actual campaign.
Each player must rally the several daimyo of his coalition, managing the morale and motivation of each clan. The forces are dispersed, and while there are reasons to unify them, the objectives are also dispersed (and the time frame compact) so skirmishing will occur all over the island.
See here for changes in the 2nd edition, including a change to the initial setup (which can be used in the 1st edition as well).