This is a great site for chemistry fun while you learn. They have multiple games, most free if you want to print your own.The card game that I am using is 18. It is played like 21 or blackjack but uses metal centers and ligands to get to 18. A fun way to teach 18 e- rule and familiarize students with ligands. My husband suggests using Dove squares instead of the optional benzene "chips" for "betting" which I think will make it very competitive.
Slap count also teaches counting 18 electrons.