“If you’ve ever heard of Diplomacy, chances are you know it as “the game that ruins friendships.” It’s also likely you’ve never finished an entire game. That’s because Diplomacy requires seven players and seven or eight hours to complete. Games played by postal mail, the way most played for the first 30 years of its existence, could take longer than a year to finish. Despite this, Diplomacy is one of the most popular strategic board games in history. Since its invention in 1954 by Harvard grad Allan B. Calhamer, Diplomacy has sold over 300,000 copies and was inducted into Games Magazine’s hall of fame alongside Monopoly, Clue, and Scrabble.” More at Grantland.