Classic is classic. It's all about balance of power, which is what Calhamer was trying to make. Attacks are also slow, as there are many defensive positions, for the same reason. The classic game is supposed to be slow placed in order to allow reversals of fortune. I find this is often lacking in other variants.

I find that all the other maps often have a lot more neutrals than classic. As such, the early game is very different. It becomes a lot more about negotiation to see who can get you into neutrals, rather than for an alliance against someone in particular.

Another thing is that there is not clear divide down the middle of any other board, in the way the main stalemate line does in classic. It leads to a very different strategy to excel and play the endgame.

Interesting question. In my view, the most important strategic difference between Classic and, really, any other Diplomacy variant is the difference in stalemate lines. I would argue that Classic is the only map with true stalemate lines, the most notable being the northeast/southwest stalemate line from St. P to Iberia. However, some world maps (e.g. World Diplomacy IX, Imperial Diplomacy) do have pseudo-stalemate lines around the continents. i.e., once one power unites a continent, it is exceptionally difficult or impossible for any other power to break through, because there are more land territories for the defender than there are sea territories for the attacker.

Well the Ancient Mediterranean map real centers on fleets, because the entire middle of the map is water. Armies are particularly important in the south though.

Classic is a well rounded map, though Austria is less influential with fleets. Each country has specific hurdles to over come: Russia position, Austria's surrounded, Turkey is isolated, England is defensive, Italy isn't the best placed, and France and Germany seem to always have to bump heads.

Fall of the American Empire is underrated on this site, though it isn't very good. I've played as every 'nation' and it's not as unbalanced as i initially thought. due to the proportionally high number of SCs needed to win (58% on the map i believe) it takes a little extra work, though there are few effective stalemate lines.

Modern is a doozy, because you can build anywhere, which incentivizes stabs. Otherwise the unequal SC split has been complained about in the past, but from what i've seen the game is fairly even.

World Diplomacy: my favorite map. There is no place to hide here, and though many say it's unbalanced... just don't draw USA. Europe and South American countries are generally considered weak too, though they do have many advantages. The fun part about this game, is that the BEST diplomats will message every other one of the 16 other players, and be able to set up long term alliances. these can be the hardest, yet most fun, to win

@Amwidkle

The World Maps do have stalemate lines, though I think the Ancient Mediterranean also has some brutal defensive lines that can be made. Empire and Modern are consistently the craziest though

Although I enjoy classic, the standard stalemate lines get a bit repetitive. I really enjoy the diplomacy part of the game, so the World Dip map is especially appealing. If you're active talking, you can do pretty well as there are almost always others that fail to communicate much or only with some of their immediate neighbors. It the countries are all active, it can be hard for one player to run away with it because the others can gang up against that one, although it most games it's still possible since some anti-social countries fail to understand their doom if they don't cooperate with others and inevitably allow the solo. I've done well with Europe and USA - I think it's more about your negotiating skill than anything to avoid early death.

Modern and Fall of American Empire are interesting too, but I don't think I've played them enough to say much about them.

AncMed ends up being two 1v1 battles plus a third. Hopefully, you are the third and can control the middle before the other 1v1s play out.

Modern is very aggressive and fast due to the build anywhere option. Almost any two powers can become an early game "Juggernaut" if they trust each other.

American Empire has a lot of potential, but the corner powers are too strong. Make sure you watch out for speedy fleets (count the sea spaces around the map perimeter)!

World is fun and chaotic, but it takes way too long, is populated by newer and untested (wrt reliability & commitment) players, and as a result there are too many CDs.

Classic is the best. The Main Stalemate Line is a feature, not a bug. It takes mostly diplomatic skill to breach it which is the whole point. If you are playing a Great Power with inherent defensive lines like Turkey or England, you are a threat to everyone else and become a natural target.

I do think classic is the best perhaps because I know it so well. It's funny but I stopped playing ancient med because I ended up soloing like 90% of my games and I am too used to draws now.

I have a soft spot for modern because it is so fast paced and somewhat chaotic.