[Squirrelloid]

I'm not sure machiavellian diplomacy means no out of game consequences. A player's reputation is built on such things. And its not just backstabbing or lack thereof - a player who behaves erratically may find others less willing to deal with him. Worse, a player who backstabs seemingly at random will be much less likely to be trusted than one who backstabs for clear reasons - ie, predictability in backstabbing gives other players a reasonable expectation of when you might or might not do so.