Crusader kings is a historical grand strategy game with a focus on individual characters. You play the game as a dynasty of nobbles through the medieval period. You start out choosing some character to control and when he dies you keep playing as his heir, as long as the heir is of your dynasty. If the heir isn't of your dynasty then its game over. The Historical Immersion Project is a mod intended to increase the depth and historical accuracy of the game.
I'm going to explain the mechanics of CK 2 as I go along, so you shouldn't need to be familiar with the game to read this let's play. This is only my second game with HIP though, so I won't be able to explain any subtler points of the mod's mechanics. I'll be playing in ironman mod, so no reloading to fix screw ups or bad luck. That does mean we could have a really short let's play if our starting character dies childless, because of the no-heir-of-your-dynasty rule, but success in CK 2 is easy come, easy go, so I think it loses a little something if you can just avoid the falls.
In the next update I'm going to introduce our character and starting position.