Had a weird dream.
Jeff, Brita and Troy are playing some kind of card-based warfare game. None of the other characters were present. Troy narrated the opening, implying that he took the game very seriously. There was a title card, white text on black like out of Frasier: "So(Si)O", the understanding being that Troy's endgame strategy would play out similar to some ancient Chinese tactician who had a similar name (though certainly no one by that name exists and it is not even particularly Chinese, but maybe Si Ma Yi?). None of the other characters were present, although Abed being missing was somehow more noteworthy. Jeff was terrible at the game, Brita was having beginner's luck, Troy was teaching them and was experienced with it. It never did finish.
Anyway, after I waking up, I was fixated on the idea of a card-based kingdom-era economic/warfare simulation game. Preferably playable with a standard 52 card deck... somehow. Number cards are regions/territory/towns or whatever, the number being the relative size/value of the area. They maybe generate economic points per round and also provide soldiers based on your number cards in play. Kings provide an economic bonus when attached to a territory, as do queens (stacking bonus for both king+queen), jacks are generals and provide bonus when assailing opponent's towns. Capture/destroy the enemy's king somehow to defeat them. (Not really sure how that should work.) Jokers are mercenaries/wild agents. Capture an enemy's territory card by outnumbering it with your soldiers in an attack (soldier count isn't 1:1 for territory cards in play, but jacks or kings provide bonus soldiers.)
I thought maybe each player could have one suit but that leaves only 13 cards for them to use. It might be better if a 52 card deck is used per player but this makes the deck huge. Not sure if players should have their own decks or draw from a shared pool - a shared pool would work if only using a single 52 card deck. A shared deck, or having more than 1 52 card deck, would allow additional tactics based on suits, with bonuses or maluses or other tactics available if your territories do and do not match your king's suit ((players would pick out the king of a suit before play). Would also allow things like having additional kings of the same suit, if in play, act as heirs if your active king gets captured. Suits not represented by players act as mercenary or neutral territories and would not act quite the same as territories of your or your opponent's suit.
That's about as far as I got. Can't really flesh it out further since I don't exactly play board or card games to know what else might or might not work. Not sure if there should also be a passive win condition (accumulated kingdom wealth); having some kind of points could add some tactics for using mercenaries but would be tedious keeping track of them every round.