Total War: Shogun 2 – Battle of Kawagoe (PC) – Free
In the historical battle of Kawagoe, the Hojo clan used the cover of night to launch a swift attack against the besieging coalition of Uesugi, Ogigayatsu, and Ashikaga clans. They overcame insurmountable odds, and even discarded their armour, to seize victory against their enemies with their prowess in speed and stealth.
This DLC was a pre-order bonus but is now free for everyone. More info here.