Generally the idea in JADE is to have a lot more interesting monsters than in ADOM. "Interesting" here should mean: "Requiring various tactics in order to be able to defeat them". This partially already is fulfilled by monsters in ADOM but since there is a lot more detail in JADE, this also should allow for a lot more tactical possibilities by the player.
Templates allow me to take existing monsters and graft new ability packages (and deficiencies) to them. Undead are my first example as they will be a lot more varied in JADE. Just think about how different an ogre brute zombie is from a goblin rockthrower zombie although both share all the special powers of zombies.
For now undead share a number of abilities (which will get expanded over time as more options and abilities get added to the game):
- They are immune to confusion, stunning, diseases and poison.
- They do not need to breathe.
For skeletons this means that they are hard to damage by fire, very hard to damage by electricity and somewhat difficult to damage by acid (lacking most of the vital parts allow these kinds of damage to be highly effective). Additionally they are very hard to damage with piercing attacks and slashing attacks cause but one-half damage. Finally most of their metal equipment will be rusty, probably causing blood poisoning at some point. They are somewhat quick but not very robust.
Zombies in contrast are slow but very strong. They lust for brains and usually can only be destroyed by damaging their brains... which game-wise means that non-critical phyisical damage will only hurt them up to a certain point... beyond that point only critical hits will have a chance of destroying them completely.
Ancardian zombies do not cause zombie rot, BTW, as this IMHO is too brutal. Zombie lords might be a different story, though.
Next up are ghuls which - except for the common features applying to all undead - will be the first reason to add paralysis effects to JADE. Then we slowly get to the attribute draining, flying, aging and in many other regards very nasty higher power undead... so much interesting stuff.
The only shame is that priests, religion and divine magic still are a number of versions aways...
Oh, and did I mention animal undead :-) ? No? Oh well... you will meet them early enough ;-)