No questions are ever stupid ^_^
a) It is just chess with anime/video game characters as the pieces. In chess, you are playing with 2 rooks (pieces that can only move as far as they can forward and sideways), 2 bishops (pieces that can only move as far as they can diagonally), 2 Knights (Pieces that can only move in a 3 space L shape), 8 pawns (Pieces that can move 2 spaces forward on their 1st move, but only one forward on every other turn. And can only take out other pieces diagonally), 1 king (who can move 1 space in any direction), and 1 queen (who can move as far as she wants any way she wants). The point of the game is to take out the other person's king.
Pieces through out the game attack and kill each other to get to the king.
Each time one of these battles happens, the two characters will have a quick mock battle, with the winner already decided.
When one team gets the other's king, they win.
b) For the most part, yes, it is. It's a lot harder to enjoy the game if you don't know the characters
c) Your partner would stand on the side and when the person playing yelled: "Dark Link, Take Out Botan!" (to use a real example) My Hiei ran on.
I hope that helps ^_^