QUOTE (LockeZ @ Nov 5 2012, 07:11 AM)
If you're making a game like this, don't yank the carpet out from under the player at the last minute, and tell them, "Oh, sorry, you got 99% of the way there, but you can't actually be a hero." The equivalent of that in a game as drama would be getting almost to the end of the game, and then showing a message saying "For the rest of the game, just imagine the plot as whatever you want." In both cases, you're not following through.
And Mass Effect 3 did both of those at once. Sorry. Had to get that out of my system.
As for the topic in question, I think when the player has any significant amount of choice in the game, forcing them into a single tragic ending is conveying the message "Screw you. No matter what you do, these people will die. And you can do nothing to prevent it. Loser.". Which is, frankly, the last thing you would ever do to your audience. Not even games with downright Lovecraftian settings get away with that unscathed: almost every Megami Tensei game (Persona 3 is an exception but Atlus indeed backed off with P4) so far has at least one ending where the hero gets the chance to be a hero and save his/her comrades (mostly the neutral ones).
Now, giving a choice between having one person or another die, that's fair game if it doesn't completely come out of left field. For example, in Chrono Trigger, which was ultimately a cheerful and optimistic romp through time, forcing the player to either kill off Marle or Lucca permanently at the 80% mark in the game would have been an unnecesary, sadistic choice that disregards the game's spirit. The same in Mass effect 1 with killing either Ashley or Kaidan, however, only drives the message home, that yes, this is war and you can't save them all. It fits into the game.
What I'm planning on doing in my game is having a main character with his own personality but giving some degree of control over his actions to the player. Over the course of the game, many tragic events happen to this character (death of friends, family, rejection and lack of recognition for his genuinely heroic deeds), and the only way he can have good things happen to him if he acts villainously, such as manipulating people, choosing to murder defenceless and defeated villains in cold blood and even committing the game world's equivalent of rape (however, to keep some moral standard, the last one immediately pushes him over the moral event horizon and prevents getting the good ending unless extra-difficult special conditions are met.).
Now, how the protagonist acts is mostly determined by the player. Play too altruistically and not demand anything, and you'll end up with the protagonist having less power (in-game!) due to apathy or getting fed up with being the hero and betraying the party (leading into the bad ending). Conversely, acting evil and demanding a reward for being a hero too many times, while boosting power, leads him into villainy as well (same bad ending).
Even if the protagonist betrayed the party, the player can save him by first getting the bad ending (which involves the seemingly main villain defeated, but hints at the party's demise and keeps the world in a devastated state, with the protagonist dead), and then unlocking and completing an optional dungeon, meeting a plot-important figure and then fighting the final boss again. This eventually leads to the good ending (with the protagonist alive and finding the reward for his courage and heroism).
My intention with these endings are to give a sense of consequence to the player and remind them of the importance of the "Aurae Mediocritas", the golden balance.