During the turn-based portion of the game, you and your co-op partner each have your own turn. I only really had one other small complaint with the game, and it’s mostly a complaint inherent to any turn-based game played cooperatively. It really opens up the game to a wider group of players. Though some die-hard RTS’ers may disagree, I think the auto-battle option is a great idea so people have a choice between a pure strategy game and a strategy game with real time strategy battles. We were having an excellent time purely playing the game on the campaign map. For my and my partner’s play-style, mirroring our armies seems ineffective, so we skipped this option. To do this, however, your armies must be pretty much right up on each other on the campaign map when one of you attacks. There is also the potential opportunity, for both of your armies be on the battlefield: when one of you is reinforcing the other one in an attack against an enemy. However, you can gift some of your units to your co-op partner so they can play with you. When your army clashes with another army and you decide to take it to the battlefield, at first it appears that your co-op partner can spectate the fight, but won’t be able to actually participate as he or she has no units invested in the fight.

UPDATE: While I originally thought that co-op isn’t always fully supported on the battlefield, this isn't really the case. Part of this is because the campaign map portion of the game is more than enough of a game by itself (trust me, gaining control of all those territories takes a ton of strategy and time without worrying about actually fighting the battles as it is). I’ve dabbled a very small amount in this part of the game - enough to know it’s challenging and suitably complex, but I’m by no means an expert at it.

You can auto-battle, which has the computer weigh the strength of the two forces and declare the outcome, or you can take it to the battlefield for the RTS portion of the game.

When you attack a city or another army, you get two options for how you want to progress with the battle. You can strengthen your alliance with another clan by arranging a marriage between the two families, or you can set a clan against another by agreeing to a peace treaty only if they declare war on one of your enemies. Here you can make offers and counteroffers, anywhere from declaring a peace treaty or declaring war to demanding or offering hostages of a clan’s ruling family. This window is quite similar to the one found in Civilization games. There’s a straight-forward diplomacy window you can open whenever it’s your turn to enter negotiations with any other clans you have encountered. As far as diplomacy goes, there are both internal and external forms.

Fall of the samurai gameplay