Comment by LanceH

We used to play in 14 hour marathons on the weekend. Thirty minutes per turn. A couple things about playing Diplomacy in person (compared to online and compared to other games):

Seeing other people walk off together to talk to each other. Seeing others explode upon being backstabbed. Sometimes we played with more than seven players, putting more than one person on the same team, giving them a diplomatic manpower advantage.

The drama and tension in person just can't quite be replaced. Although the anticipation of a move when you're playing correspondence is absolutely exquisite. Burning someone in a 3 month old game is its own wonderful experience.