(also, my board game club has several kids' games in it. we make them interesting by playing them in the same way - newcomers must learn the rules by screwing up)
my rules are something like "if the person two places before you played this suit, and the person before you played that color but not that suit, switch colors and play a number that is the sum of those two numbers mod 13"
now, although it's my turn and I've thought of a really great P that I'm sure no one will get, unfortunately I need to be AFK for 10 minutes or so, so someone else will have to defend next.