Monsters' Den: The Book of Dread/Enemies

There are five different enemy factions, as well as legendary creatures and demons.

Enemy archetypes and prioritization
Each faction (aside from legendary creatures, demons, and deep creatures, which are a bit unique) can be assigned archetypes for the types of enemies they have. Knowing these different archetypes will help you prioritize which enemies to take down first and aid your game considerably. Prioritization refers to prioritizing which enemy to attack and kill first before they can do harm to you or aid their allies.


 * By far, spellcasters should be the highest on your priority list. These include the Undead Lich, the Dwarven Runecaster, the Orc Shaman, and the cult Acolyte and Neophyte. They are capable of buffing or healing teammates, summoning enemies, cursing, stunning, poisoning, and in short making life harder for you. Thus, they should be taken down first. They generally have the lowest health in their faction, so that's a plus.
 * Next should be the tanks. These enemies are characterized by greater health, powerful attacks, and slow speed, such as Bone Horrors, Trolls, Chosen, Dwarf Veterans, Voidstalker, and Aetherguard. If there are more than one tank enemies, it would be actually be advisable to eliminate one as fast as possible to forestall serious damage to your party.
 * Following them should be the melee troops, including Skeletons, Dwarf Warriors, Dwarf Maniacs, Orc Champions, Orc Berserkers, and Guardians. Generally they are only a problem en masse or buffed by an ally, but focused, concentrated damage on them will take them down.
 * Last are the skirmishers. These are ranged, generally speedy troops, including the Undead Archer, Vampire, Dwarven Crossbowman, Goblin Artificer, Orc Savage, and Protector. The Wraith can be considered a skirmisher because of its ranged abilities and quick speed, but they are so easy to take down with a magical attack that they should be taken down first.

Each faction also has two different boss types, a melee boss type who stays on the front lines, and a ranged boss type who may be good at buffing his underlings. They are characterized by immunity to instant kill, massive health, and powerful buffs or attacks. In prioritization, bosses should always go after spellcasters (the last thing you want is a buffed boss). Most of the time, it's best to kill all his underlings before the boss himself, but if you know you can tack on a lot of poison damage or easily deal a lot of damage to him, it may be advisable to do that first. Area of effect attacks are always helpful in boss fights, helping to soften the defenses before going in for the assault.