The guys over at The Chronicles of Spellborn have released a nw Dev Journal. This time around, thye're talking about Mob Behavior.

ll though the title might suggest that this is purely an AI related journal, I’m going to stick to the gamedesign side of the subject. Or at least, try to.
I’m also going to try and not just give the situation of Spellborn, but rather talk about possibilities and why I think some choice are good or bad.

Goals
First some goals must be set, what do we want to achieve when a player fights a non-player (mob). Should the mob fight back or maybe run away in fear? If there is a fight, what should the player experience?
A challenge? Okay, but easier said then done, challenge because? Mob hits hard or mob is hard to hit, mob heals itself or does the mob have a couple friends waiting around the corner? Besides, making something a challenge doesn’t necessarily make it fun. So, the goals will have to be thought through and might evolve a bit during the early stages of the project to achieve the desired ‘vision’ which they all contribute to.
Combining all these goals will actually decide a large portion of the core gameplay so getting them down on (digital) paper is of the essence. Goals should be clear and simple, so everybody can easily understand them, yet they should cover every aspect and leave no questions unanswered.
As an example I will handle a (well known) goal set for Spellborn.
Never should a player be just as effective with his hands in the air as on his mouse, keyboard.

Check out the whole thing here.