[zenvidar]

This idea would significantly increase the benefits of roleplaying. The way your character behaves would change the way the game handles things. It would need some very advanced coding which I could never imagine to wrap my fingers around, but it would be breathtaking.

If a cleric always goes around healing his buddies instead of sick NPCs and players who come to his deity's temple, problems break out.

Now, allowing players to actually cause a little harm could do well too. Obviously not allowing players to destroy everything, but maybe allowing NPC pickpocketing in the MMO version. A shop owner's stock of weapons went missing, so you can't buy your new sword to go out and try to stop a band of orcs marching on your town. (more realistic NPC enemies that move across area transitions on their own towards their desired goals would be cool)

Now that you and the other heroes in the town can't upgrade, you have less of an edge on the enemy. More NPCs die and part of the town gets destroyed before you finally defeat the enemy.

In addition to factions, having a truely viewable impact would be something to drool over and would provide some amazing roleplaying opportunities.