Castles & Crusades Players Handbook #7

You’ll find with C&C that the game is easy to play, but more importantly is its versatility. You can take your house rules and drop them right on top of the C&C mechanic (the Siege Engine) and keep on playing. You are in control. Take the advantage/disadvantage system from 5E and use it with C&C. There’s nothing stopping you. What’s even better, because the whole game is driven by attribute checks that have only loose guidelines, the game master chooses what attribute check the player rolls. If they want the wizard to swim better, make the character roll an intelligence check to swim the river. It’s your game. Take it.