A computer StoryTeller, on the other hand, has to expend considerable energy handcrafting locales beforehand. He has to write an entire description from scratch, including as much detail as the most curious player might desire. For this reason the computer StoryTeller has to figure out ways to constrain his world, so that he doesn't have to describe entire kingdoms or continents. Setting is less dynamic. In a novel or an RPG the setting influences the main characters and in turn the main characters can influence and change the setting.
Dynamism is a huge topic of discussion in the online game community without any good solutions.
At heart the computer StoryTeller needs to be quite aware that his setting will rarely change. That quick description should make it clear that characterization can be a tricky problem in RPGs of all types. Sure, you can ascend to the tenth level of experience or become a Knight of the Round Table or gain possession of a soul-sucking ebony runed blade. Thus when you, as a StoryTeller, are thinking about characterization, one of your primary goals has to be figuring out how you can encourage players to let their characters evolve and change as they should when they are faced with stunning revelations and life-threatening encounters on a daily basis. You don't ever want to make players change their characters, but you do want to plant those seeds in their minds which encourage them to do so themselves.