ChessVariant: 9. 10x8 version with 8 knights, 8 bishops, 8 rooks, 5 queens, 5 marshalls, 5 cardinals and 1 amazon each.
10. 10x10 version: throw in some zebras, camels, nightriders and other fairy chess pieces.

And each variant can be "wild": the system determines how many of each type each player gets (still filling the board of course, and each player gets the same set of pieces): for instance 4 knights, 10 bishops, 5 rooks and 13 queens.

And then we throw in darkness (you cannot see your opponents pieces), atomic, extinction, dice, we let the knights relay, add a behemoth and a cheshire cat, and we'll have the greatest game ever!