| Avalon Hill board game that uses the same basic rules as Diplomancy, but with a few additional elements thrown in to cause you even more brain wrecking havok.
Machiavelli is set in 15th and 16th century Italy - you play either one of the more powerful Itallian city states (the Papacy, Florence, Milan, Venice or Naples) or one of the foreign powers with interest in Italy's land (France, Austria or the Turks) in a decided time period - each time period giving very different initial starting points for the different rival powers.
Unlike Diplomacy, which involves no random elements at all, Machiavelli throws in Famine and Plague which sweep the land during Spring and Summer respectively, radically altering your plans and defenses as whole armies are wiped out and cities made inhabitable due to food shortages and rebellion.
Machiavelli also adds a money system which includes such cruel elements as bribing enemy troops over to your side, starting rebellions and assassinating rival leaders.
All in all, I've found very few board games as capable of captivating 8 people for 20 hours at a time. The only major drawback to Machiavelli is that the game is virtually impossible to play with less that six people. | 
