When starting a game of CoE3 you have to choose one of 17 classes to play. They vary widely in their abilities and what kind of resources they need to conquer.
Necromancer
At first the necromancer needs corpses to reanimate in huge amounts. Conquering graveyards or battlefields makes for a very good start. Otherwise towns or large villages are ok. Later on he needs Hands of Glory to summon powerful undead or to transform himself into a vampire or lich. The Hands of Glory can be found in larger towns.
Druid
The druid mostly needs herbs that can be gained from forests and jungles. Later on the druid is going to need an ancient forest to summon the legendary beasts.
Troll King
The troll king is a very powerful unit that can conquer villages and the more weakly defended mines all by himself. This is good, because he need both gold and iron to recruit more trolls. If he cannot get hold of trolls he will have to do with ogres and goblins until he can get an iron mine. If his mother should appear it will be useful to collect fungus from swamps and forests as well. With the fungus the troll mum can do rituals to scry or awaken the forests.
and then there are 14 more classes.
