I was thinking about different kinds of personalities randomly chosen and applied by that awesome AI the devs keep hinting on about. So yes, not whole villages, but some of the villagers while others will take their rusty sickles and scythes to fend off the attacker (i.e. you). And city dwellers will run to city guards. Or try to hide behind those barrels in that alley.
Yes, I agree that having ground-breaking advanced AI would be fantastic. I can't wait to find out what AI the devs are using!
I think that, in practice, such AI would be possible by constructing huge neural networks. The same network could apply for every single NPC. It is important to have a single framework that is both extensive and extensible, allowing all behaviours for an NPC to be automatically generated procedurally (whether during development, or in-game on-the-fly, allowing more varied game experiences).
In practice, such a network would involve an observation->response, or action->reaction cycle. For each observation (e.g. see a man with a sword), there would be a potentially-large number of potential responses (e.g. run away; attack; ignore; sit down and cry, etc.). The response would be chosen stochastically, with predefined state transition probabilities. Each transition could optionally have a pre-defined base level probability (e.g. relatively few people would sit down and cry, hopefully).
Importantly, different NPCs could automatically have vastly different "personalities" by assigning them different state transition probabilities. This assignment (or, rather, relative adjustment) would be done stochastically upon NPC generation. Of course, certain transition probabilities would be dependent on more general traits (such as bravery, cowardice, stupidity, gluttony) and thus would be highly correlated. This correlation would have to be taken into account, otherwise you'd get some interestingly bipolar NPCs! Bring on the crazies!
Also, it would be important for state transition probabilities to be allowed to be dynamic in-game. This would allow NPCs to intelligently learn from their experiences, changing their future actions based on their past behaviour. Also, it would allow limitations on certain transitions (e.g. legs got chopped off -> can't run away!).
This would also allow various types of NPCs, e.g. humans, wolves, birds, ogres, etc. to be treated as part of the same framework. Impossible choices (e.g. humans can't fly away; wolves can't set fire to things) can simply be treated as zero-probability options. Anyway, I've rambled too much...
