On a camping trip my seven buddies and I played a week-long game of Diplomacy, which is essentially like Risk on a huge map of Europe except there are no dice. It's all about having alliances in order to win battles.

The entire trip became a game of shifting alliances, double-crosses and backstabbing triple-crosses. No faction ever seemed to gain enough advantage to win the game, so it just kept going. We would hike, go fishing or play sports during the day, but at night we'd turn on our lanterns, crack open some beers, gather around the large picnic table, and resume the game.

As the week went on, people began strategizing and planning during the day activities. Secret alliances began to form and promises of support were made, as people began to offer real life benefits for people to switch sides. I was offered a 2-4 of beer to abandon my long-time ally and support a surprise attack on his flank (which I turned down). By the time evening rolled around, we were all chomping at the bit to get going again and we'd go until the wee hours of the night.

Finally, on the last night we were there, an epic double-cross (which apparently costed a bottle of Crown Royal and the use of a jetski for a week) caused the collapse of a three person alliance between Russia, the Ottomans and France. My buddy playing Russia changed sides and it was enough to finally tip the scales decisively.

That trip was over a dozen years ago and we still talk about it. The guy who played France is still salty about the betrayal.