I know of Mafia/Werewolf, but they are too arbitrary for me. Diplomacy (the game, yes) puts some substance underneath the negotiations --- some alliances are easier to pull off and more natural than others, but they can all be made to work.

Also a honest and straightforward approach often works best. Or more accurately --- in the vein of Machiavelli --- being known for an honest and straightforward approach, which is not the same thing.

P.S. Please pardon that I only wrote "the game". I am too much involved in "the hobby".