Fresh off of my finishing the currently published portion of A Song of Ice and Fire, my braincauldron has tossed out an idea for A Game of Knights and Suchlike! (very minor pluralization-based spoilers ahead)
One of the interesting points of aSoIaF was that the kings fielded armies not by recruiting directly, but always by courting the loyalty of the various landed lords of the realm. As such, players would recruit a set of lords, each of which would have an attendant set of knights, archers, crossbowmen, footmen, etc.
Lords main stat is loyalty to the player; loyalty is based initially on the lord’s opinion of the player - lords will be concerned with a single aspect of the player, either their bloodline, skill at arms, or riches. Loyalty would change over time based on pay, battles won, battles lost and other such potential modifiers. Loyalty would control how long and how well and how long a given lord would fight, a sellsword being less reliable than, say, a close and well-loved blood relation. Their other primary characteristic would be, as previously mentioned, the type and number of troops that they have with them. Additionally, lords could have friendships and rivalries with other lords in the deck, and other such personal quibbles that affect loyalty or whatever else.
My immediate idea was a card game where players first spend points to customize a king, and then draw from a deck of lords, the randomization preventing players from stacking one stat. Additionally, another stat attached to each army (supply?) would serve as another balance, in case one player gets utterly hosed by their luck of the draw. However, unit positioning is really important in medieval battles. (did i mention that all this was midieval-tech? no? Hm, that’s probably an important detail. On the other hand, SPESS FEUDALISM could be cool too. Possible reskin-alternative :D) The positioning detail could be solved by a game board to place and scoot the lord-cards around on, or by a transition over to a Warhammer (fantasy) style tabletop, where the units under one lord’s command move around in a formation-block, or a combination of the two wherein troop blocks move around a board of squares. Also, there’s a potential metagame/overgame attachment, which tracks the armies and relevant VIPs between battles over time.
In addition to being a game, this would also be a wonderful chance to doodle a lot of coats of arms! :D