How do you guys personally feel of a type of story that explains a lot of the core things that appear in the game, but neglect to tell you whether or not you're the good or bad guy, or leave it open to speculation on whether or not what you're doing is beneficial or detrimental to yourself, others, or the world around you?

Would you consider a plot line where the conclusion is open to interpretation and your actions could have two polar-opposite justifications and implications a plot that can become a success?

Or do you feel that a successful plot eliminates most, or all, ambiguity?

What are your personal thoughts on it?
Has there been a game that you remember with a good plot line that happened to be ambiguous?

My perspective is that the objectives should be somewhat clear, but it's fine for the motivations and the "truth" of the situation to be ambiguous. Gamers should be able to express their views and motivations, as most gamers never truly roleplay their character in the game. Clear decision points allow the player to take the game the direction they want to, although I think it's fine if they can't predict the effects of their actions.

in my opinion this sort of thing requires balance. Ambiguity can add great depth to the game making the gamer feel more like his/her character, and provides a good way of including decisions. However to much and you have a confused player who has no idea whats going, no goals, no motivation.

As for a game that his this, I have to say Deus Ex. Brilliant game, it forced the player to make decisions, act on instinct, decide whether he/she is doing the right thing, all that sort of stuff. If you haven't already take a gander at it mate, its awesome!

My perspective is that the objectives should be somewhat clear, but it's fine for the motivations and the "truth" of the situation to be ambiguous

To be "the good or bad guy" is just one of many objectives a player may seek to attain. I think you may need to find a suitable replacement if you wish to keep the morals ambiguous.
For example, ala sword and sorcery, offer them an objective to become the strongest man in the universe.If you offer them a different scale against which to measure their options, they won't be tempted necessarily to verify whether this is a morally good or bad decision. For the most part, they will consider these decisions from the standpoint of the objective they have set for themselves or that you have set for them.
Finding the truth is another pursuit for the player. Look at tv series, such as House. People like House despite his moral conduct because his decisions make sense according to his own guide. His scale is finding the truth. He wants to reach the end spectrum of the truth. As a result, and since this is the scale against which he judges his own actions, he doesn't give a damn about the moral orientation of his actions for the most part, and as a result, the viewer, which is entitled a priviledged position and insight into this character, feels most of his actions are justified.

I think you just need a strong theme and one or many options for the player to change the scale against which they will judge their actions on.

I tend to be bothered when a game's story brushes over too many details in the name of "ambiguity." Although it may not actually be the case, it often comes across to me as the writer just not bothering to (or wanting to) flesh out the story of his game, relying on the player's filling in the gaps to give it some amount of depth.

(The worst, though, is when they use ambiguity to try to fabricate a sense of philosophical depth. Kingdom Hearts I thought was especially bad about that--although it's been years since I played it, so maybe my opinion would be different now.)

Now, if the player's decisions in the game cause the story to go one way or another--and the only "ambiguity" is in which path is considered canon--then I'm totally cool with that. I just want there to be something substantive.

Would you consider a plot line where the conclusion is open to interpretation and your actions could have two polar-opposite justifications and implications a plot that can become a success?

That's already been done in the most recent Sam and Max season from TellTaleGames called The Devil's Playhouse. There are two different polar-opposite endings for the last episode in the season(based on how you reason with the main antagonist) that could make a big difference for the next season.

It's also been done with Star Wars: Knights of the Old Republic


There's always Monkey Island 2: LeChuck's Revenge. Until The Curse of Monkey Island came out, the ending was very puzzling.

Don't forget TellTaleGames' SBCG4AP. The ending for Eight-Bit is Enough is confusing at the very least.

Alongside those, there's that Back to the Future season, also from TellTaleGames, without a clear conclusion. I guess that's just what to expect from a time-warping series like Back to the Future.

Who could possibly ignore the (in my opinion overrated) The Legend of Zelda: Ocarina of Time? Until the director of that game told everyone what they say happened, there were multiple theories about the ending scene.

As you can see, there are plenty of awesome games with the conclusion open to interpretation.

As far as I can tell, the only game that I have played where you don't know if you are good or bad at some point is Pokemon Mystery Dungeon: Red Rescue Team, but that question is answered by the end. I guess a twist is not ambiguity...

It just depends on how well you write. If it's predictable, you won't have much ambiguity. If it's not interesting, no one will care.

Went to a presentation at BAFTA a couple of months ago, by the developers of Witcher 2.

They said that one of their core concerns in developing the game was the impact that the player's decisions could have on the game universe (in other words exactly the sort of ambiguity you were talking about).