I hold the opinion that games like diplomacy don't work as well online because there is a lot more pressure when you are talking to someone, in person, on the other side of the table, making a deal. We played at the store and I ruled at the game. Basically, I made an alliance with one person that was public knowledge, but then I made a secret alliance with another player to stab my open alliance in the back, while I had a second secret alliance with my open alliance that I would be stabbing my first secret alliance in the back. It was fucking awesome.