Kotaku - Weighing Morality in Gaming Editorial
An editorial at Kotaku named Weighing Morality in Games discusses how games have used and uses this when forcing the player to make choices. Games mentioned are The Witcher Alpha Protocol and Mass Effect. No games prevous to these are mentioned, KOTOR, BG1 or Fallout. Here's what the author says about Mass Effect:
There are few developers, however, that have made the transition from merely allowing the player to affect the physical world to enabling him or her to influence the people and events in that world with more than a gun, sword, or spell-book. Of these, Bioware's Mass Effect games are perhaps the purest example of how these kind of systems have been implemented thoughtfully and effectively. There are real consequences that the player has to live with, and they carry over throughout the series. Players can choose between morally good (blue) and morally questionable/renegade (the choice between playing as Luke Skywalker or Malcom Reynolds) with a neutral choice in between. The player can always choose either good or bad, but persisting in one type of choice long enough unlocks a kind of super-powered good or bad choice later in the game.