One of my characters in Star Wars: The Old Republic had to decide whether or not to kill a man. Doing so would have been a betrayal of the most vile caliber. This man may have been in the employ of a Hutt crime lord, but after hearing the sincerity in this man's voice during many conversations I felt he was as decent a sort of person as I could expect to find on the gangster planet of Hutta. He was a man so appreciative of my assistance that he wanted me to meet his sons as a sign of respect and gratitude.
The character of mine in question is an Imperial Agent. He's duplicitous, conniving and ultimately out for himself. He also knew that a Darth, one of the high ranking Sith that rule the Empire, was personally watching his mission. My character therefore chose to gun the man down because a Sith would appreciate bloodthirstiness. I could have tried to help the man out instead. I had the option to do so, but instead I killed him in cold blood and immediately felt terrible about it.
Normally when I play role playing games I play through once as a good character before playing through again as an evil character. I've switched it up with The Old Republic but old habits die hard, thus my regret upon killing that man on Hutta. Had I been playing a traditional RPG I'd doubtlessly have reloaded my game and made a different choice to alleviate said guilt. MMOs don't allow for reloads, so I assuaged my conscience by reminding myself I'd merely played the role I'd chosen. In that moment I knew Bioware had achieved their goal, as told to me by Lead Writer Daniel Erickson and Game Designer James Ohlen at E3 in 2010 and 2011 respectively, of recreating the experience of tabletop, pen-and-paper role playing games with The Old Republic.
Another good example of Bioware's success in achieving this goal is how role playing can affect quest structure. When groups in The Old Republic interact with NPCs, each player in the group selects a potential response after the NPC finishes speaking, and an under-the-hood die roll determines which group member's response is actually selected. In one "flashpoint encounter" designed for groups, the choice of whether or not to kill a man determines which of two directions the quest will take. When a choice of quest path depends on who gets to speak next the experience might be frustrating for some, but it's a delight for anyone who has played pen-and-paper role playing games and tried to confound the desires of fellow players by role playing their character properly.
By fully-voicing all the cutscenes in The Old Republic and introducing its signature RPG morality system Bioware has made a fundamental change to our perception of what an MMORPG is capable of, but the most interesting affect of this change for me is how starkly it throws into focus all the dated aspects of the genre which Bioware did not change. I recently described the game to a friend as "an MMOPRG with a Bioware story stapled onto its back." The more I play The Old Republic, the more accurate my off-the-cuff response feels to me.