Thanks for the responses! The questions from the first post still stand, but I’m going to react to some of you and tell you how I think that we may be able to be inspired by RPGs.
Emily: those are very good observations: part of the fun of RPGs is improvisation and having an audience. Improvisation is hard to achieve on IF, and presumably not worth the trouble. I wouldn’t underestimate how much the game itself is the audience when you play IF, though. As an example, “Losing your head” is famous for the part where you can kick a head around. I believe that this has no positive impact on the story, doesn’t solve any puzzle, or whatever. So why do people find it cool that the game recognises “KICK HEAD” and reacts appropriately? Because the game (the author of the game) becomes an appreciative audience to what you thought was a funny idea.
However, there is more to RPGs, and what the ‘more’ is depends on the RPG. It is probably not so useful, as you indicate, to look at specific mechanics. You don’t really want to implement the combat system of D&D in a work of IF, for instance. But you might learn something else from it: say, resource management. If I remember correctly, David Whyld used hit points in his Spring Thing 2006 entry as a resource that allowed you to get past puzzles that you were unable to solve. His mechanics were different from how D&D implements hit points, but the underlying game idea is basically the same - there is a resource that dwindles whenever you act suboptimally.
As another example, consider the modest indie-hit “Dogs in the Vineyard”. The central dice mechanic of this game is rather complicated, involving dice of several different sizes that are used in a kind of bidding contest. Implementing this in a piece of IF would be impractical, to say the least. But let’s consider what the point of the mechanic is. It is constructed to lead to the following two situations:
(1) Sometimes, you can only win a conflict by putting your own health and possibly even life on the line. This raises the question: what are you willing to risk for this cause?
(2) Sometimes, you can only win a conflict by escalating to fighting or shooting, which involves the risk of hurting or killing your opponent. This raises the question: are you willing to kill for this cause?
Are you willing to beat up your nephew to make sure he stops drinking? Are you willing to shoot at your own father to make sure he doesn’t lynch the escaped slave?
Those questions could be implemented in IF, though you would have to device a different mechanical way of doing so. (In this case, you may not need new mechanics at all. You just have to make sure that the player clearly sees the two possibilities that lie before her and knows that the choice is really, really hers.)
Just thinking aloud.