Crusader Kings for me, is a little like Dwarf Fortress. I can smell the amazing game that sits atop that stupendous learning cliff. I can see the edge of its toes poking over the edge and it's enticing. I know it's there.
I just can't get there. Before I surmount the Wikis and tutorials needed to learn how to play the game and understand its many nuances, I'm bored and off playing something else.
Fortunately not everyone is in need of such immediate gratification as I am, as there are a lot of people that love playing Crusader Kings and more specifically its sequel Crusader Kings II. And the developers know that, which is why even four years on they're still releasing new content for it, making it harder in some ways, but also offering interesting avenues of progression too.
The new content this time around is called Conclave, but it doesn't add new countries, factions or military options, this one tweaks relationships, introducing new education and diplomacy systems, which makes it more possible for your most trusted friends and allies to stab you in the back,
Hurray!
Don't trust your siblings. That seems to be the message there.