of Good Diplomacy
The purpose of this article is to show the advantages of being a neutral race
and the disadvantages of being aligned with either good or evil. While the
Highmen and Undead may have the most powerful units, they encounter many
diplomatic difficulties by being pure good and pure evil.
~ CorshalBlue ~
There are 5 possible alignments in Age of Wonders:
Pure Good ---------- Good ---------- Neutral ---------- Evil ---------- Pure
(1) --------------- (2) ------------- (3) -------------(4) -------------(5)
Pure Good: Highmen
Good: Dwarves, Elves, Halflings
Neutral: Frostlings, Humans, Azracs, Lizardmen
Evil: Orcs, Goblins, Dark Elves
Pure Evil: Undead
In general, you have a chance of encountering 12 possible race cities whenever you go out to conquer places the first time. Note that creature units of any race will happily serve any other race as long as they arent 2 steps away on the alignment table (pure good=1, pure evil=5, neutral=3). Also note that you start most games with a set diplomatic race relation with all races on that map; lets take a look at the "numbers."
Every race that is aligned as good or evil (which we could call 2 and 4 on the alignment table), willat the outsetget along well with 5 races and really well with 3 races, and they can usually use the creature units from those races as well. The pure good and pure evil races (1 and 5 on the scale) only have decent relations with 3 races, and only get along really well with themselves (except for Highmen, which remain on good terms with the humans).
The four neutral races get decent relations with 6 races and get along very well with 4 races. As you can see, there is a huge difference between being pure good/evil and being a neutral diplomatically. If you play a pure race, the chances of capturing cities that will be happy with you without revolting and being able to use their creature units without poor moral is not very likely. This means you will be doing quite a bit migrating, which not only worsens relations further, but costs valuable time, money, and resources. In the 4-5 turns it takes to migrate a hostile city, A neutral race will usually be upgrading or installing new units. Migrating cities also kills all the gold it usually produces while migrating is in progress (which on average always ends up to losing around 100 or more gold), which, again, neutrals dont have to worry about. Finally, migrating is rarely done without having to worry about revolution, which costs units to act as garrisons which neutrals can use to scout ahead, find more resources, or to help fight in a battle or siege.
Creature usage is also a factor. While its possible to be the Undead and work on your relations with the Highmen to the point that a Highman archer will actually LIKE serving you, you will NEVER be able to use a creature of pure good without a high chance of desertion (e.g., the Valkyrie). To determine whether a particular unit is a "normal unit" or a "creature," select the unit and look at its profile. It will tell you the race the unit belongs to, its alignment, and whether or not its a "creature."
Last but not least, being a neutral means you cant be hurt by the champion spells which attack only good or evil units.
Well, thats all; I hope I brought to your attention the rather steep disadvantages the pure races have when it comes to diplomacy. Disadvantages that cost them time, money, and resources that neutral and not as sharply aligned races rarely have to worry about. The Highmen and Undead may have the most powerful units, but they certainly have to pay for it dearly when dealing with other races cities and units.
ADDENDUM added by Flinx:
If your leader happens to have at least three Life-Magic spheres, you'll be able to research the spell "Tranquility" (global enchantment). This enchantment makes any sort of Diplomacy much easier. It may take some days to fully take effect, but in the end result is impressive. Even with a pure good race, you are able to capture pure evil towns, who are content (or even cheerful) with your occupation.
Remember that while it mostly helps you, Tranquility--as a global enchantment--cheers up relations between ALL races - even you enemies! While I had not problems using this spells in single player games, it might be counterproductive to your goals in multiplayer games.
The spell worked best for me during the Keepers Campagin (good path), and was my first spell to cast on every map.