Eldar said:
* Planescape is my favorite game. The main character was set, but the player could take that main character along different paths. Does the spirit of this article speak against such a scenario? Does the idea of freedom controvert the idea of a set main character?
In my estimation, it's not contradictory to the spirit of this article.
Planescape was designed such that your past was set to a certain degree, and not only were you given enough freedom to determine your future actions, but you had a healthy amount of freedom in expressing how you felt about your previous actions.
The PC may still hear about things he or she has done, and be blamed or lauded for them, but in reality, the player herself did none of those things. In a way, it's almost like it's a separate character that the PC is interacting with (in an abstract sense, of course). The PC is still free to determine how they feel about what they have done, and to create their own vision of the character, independent of what may have transpired in the past.
Eldar said:
* Can technology, either now or in the near future, hope to permit computer game design of this nature?
I don't know if technology is really that much of an issue. Rather, it would seem that the primary limitation of RPGs is generating the incredible amount of material associated with multiple independent storylines with interrelated side quests...
...and if you want to make all of that stuff _good_, that takes even longer.
Eldar said:
* How difficult is it to work with various rulesets or settings to achieve some of these design features?
I'm no gamedev (but I'm working on it, since I graduate this May :/), but it should be possible to lay out any given setting such that this theory of design is applicable. If you're working with a predetermined storyline, it may be difficult if not impossible to lay out the plot such that it allows for this, but you still accomplish something, even if it involves a lot of smoke and mirrors (i.e., Deus Ex).
Rulesets, at least in the sense of D&D, White Wolf, etc, typically allow the player plenty of freedom in creating their own character. Obviously, there are some differences; different rulesets allow players a certain amount of latitude in determining how competent, experienced, or powerful their character is.
Most tabletop rulesets are designed so human beings can process them in a relatively short period of time. Sometimes they have to make approximations or simplify calculations in the name of playability. Computers don't have that problem, which means if you want to take a given ruleset and throw in some extra complexity, you can usually do that without tampering with the core mechanics.
A good example of this might be creating a reputation system in a computer game implementation of D&D 3rd. Even if it's outlined somewhere in some sourcebook someplace, it would be a pain for the DM to keep track of an NPC's opinion of a PC numerically (let alone the fact that it shouldn't be all that necessary, if the DM knows how to role-play properly). Conversely, computers can't role-play very well, but they are very good at keeping track and crunching numbers, so a reputation system thrown in based on existing D&D mechanics wouldn't be a problem.
Beyond that, I think I could see how your question requires a more complex answer, but an example would be helpful.
- Tra'Hari