I just stumbled upon this Squidoo lens yesterday, and it's one of the most interesting I've seen in a long time. There are several web pages out there about ancient Roman games, but this guy has taken the time to re-create a game board and explain the rules - and it seems a pretty nice game to play. So go check it out:
How to Play the Game of Rota (Ancient Roman Tic-Tac-Toe)