Ordinaryundone said:
Rape as a plot point? Sure.
Rape as a gameplay feature? HELL NO.
A perfect summation.
The subject matter is actually one which has frequently been implied (but seldom explicitly alluded to) in several games, and fairly often it's done in a manner which paints the perpetrator as a complete bastard. It's the fastest way to make the audience hate a character, regardless of medium. Implying or stating it's occurrence is fine in a game, provided it's handled appropriately.
Allowing the player to commit the act? It's generally portrayed as sickening already, and there is some justification for it never being justifiably implemented into a game. Even in the case where they're trying to illustrate
the player as an irredeemable monster... yeah, there's always some moron out there who will take it as a good thing. The media has a tendency to blow everything out of proportions, but the touchy-ness of this particular subject does mean it almost certainly shouldn't be included in a game's design.
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Now, onto two senarios which are a little more difficult to consider.
Senario #1 - Showing the scene as a cinematic in the game.
Very touchy territory here, but it could be done in games which permit sex scenes already (rated appropriately, of course). Chances are such a scene would greatly disturb the player, but that could be the entire point. Nevertheless, this particular use should be used sparingly and never off-handedly.
Senario #2 - Including it as an interactive gameplay element, but having the player as the victim.
Okay, this one is possibly the most touchy version of them all,
but it could be the perfect way to portray the act as horrific and irredeemable. Obviously, this would probably be a form of "controlled helplessness" (and could be done from a first person perspective); to say the player is guaranteed be disturbed by this occurring would be an understatement...
but that would be the entire point.
The next question would be
"Is Senario #2 going to far?", and that's quite difficult to answer. In an age where most player characters are escapist characters, it would be the ultimate subversion of that idea; something so jarring that it couldn't be emphasized more. Still, it's a question of if any developper would be willing to do it (even if for the right reasons) and if the player(s) could handle it (or would that go against what it's trying to do?). Anyhow, that's something I'm not so sure of... but it would be the only reason for someone to include it as an interactive element.