Colonia VII-B

A vital lesson any aspiring game designer must learn is that relatively small tweaks to the rules of a game can produce major changes in the feeling of play. Diplomacy variants are one good way to see this quickly; since the game's publication in 1959, fans have designed a huge number of variants (or 'mods', if you will), and by exploring them, you can see a lot of ideas for how to change gameplay very quickly. Excellent places to explore them include The Variant Bank and The Diplomatic Pouch.

Diplomacy is, in many ways, a superb game, but it is not without flaws. Among them, two are prominent. First, it is fairly easy to be eliminated in the early game, which is a pain, since a complete game takes seven hours or so to play, and your friends are still having fun while you're looking at your watch. Second, because of the high ratio between supply center and non-supply center provinces, it is fairly easy to construct a "stalemate line" -- a continuous line of mutually supporting units such that no attack from the other side, however arranged, can break the front.
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Colonia -- the "VII-B" indicating how much work Hyatt and others put into refining it over the years -- is perhaps my favorite Diplomacy variant, mainly because it redresses these flaws. It covers the entire globe rather than Europe alone, notionally in 1750 rather than 1900; the powers are Austria, China, England, France, Netherlands, Ottomans, Portugal, Russia, and Spain. Except for China, all powers (yes, even the Austrians) have some "colonial" supply centers outside Europe; this produces two positive results. For one thing, the array of powers in a particular region may be quite different from that in Europe, so that it's typically important to negotiate with everyone, rather than mainly with your neighbors -- or rather, almost everyone is likely to be your neighbor somewhere. Second, even if you're crushed in one area of the globe, you may survive elsewhere -- England might fall, but the English possessions in Asia be expanding nicely -- so players can survive longer in the game.

And in addition, Colonia has more non-supply center provinces, relative to the number of supply center provinces, than conventional Diplomacy. This makes stalemate lines more difficult to construct, and therefore produces livelier play in the end-game.

Colonia's flaw, of course, is that given the much larger board size, it takes longer than conventional Diplomacy to play -- and Diplomacy is already far to lengthy a game for most people. But in postal or email play, it's quite nice.