Sparing you my extensive thoughts on the definition of end, replay, and branching stories in terms of games, I still have some ideas I would like to share. I get easily frustrated with games with branching storylines, because it's almost always such a stupidly small issue that makes such a disproportioately large impact on your gameplay experience. Let's take the iconic example of a fork in the road, and if you go left you play one level and if you go right you play another. Or let's say that the end of a game changes depending on whether or not you decide to collect a powerup after killing a certain diving suit wearing miniboss. In either case, in my opinion, the game places too much influence on one relatively irrelevant factor. Now, I really like the idea of a branching storyline. It's cool to have something extra to go back and play, and it's cool to think that my approach can affect my experience more than just incidentally. And I still do like to see otherwise unimportant factors I wouldn't normally call core gameplay make a difference. And I even enjoy how in Metroid depending on how fast and complete you beat the game you're rewarded with a different cinematic. But I was rather disenchanted when I played Cave Story and discovered that to save the professor's life I had to ignore the fact he was injured, and then follow a series of bizarre motions that made little intuitive sense to be able to have the "good" ending. I enjoy that there was a better ending, but I had problems with how it was done. Now, the intuitive issue is just a matter of good game design, but I still haven't played any games that really pulled off branching stories well in general. Anyone know of any off hand? I was thinking specifically about small choices making a big difference. I don't like that making a selection at a dialogue box should be able to significantly effect the outcome of a game. But I also hate when everything is totally reversible, like in Fable, and it's still frustrating when the changes are absolutely discreet, where you're either a saint or a villain, like in every game in the past decade that's had some sort of alleged moral choice system. No, I was thinking more along the lines of a game that would acknowledge your lesser accomplishments as part of a grand tapestry of win you weave through actually completing the bugger. Does anyone have any thoughts on branching storylines in games? Has anyone played one that successfully pulled of a scripted plot with legitimate moral decisions? Or where the decisions you make don't boil down to something totally stupid?

There are more options fro story lines than branching and non branching, and some of these other options might be worth looking into, but for now I will stick with branching.

The key to a good branching story line is the same as good game play: Make the choices significant and interesting.

In the example you provided you can see this yourself. In the games where the decisions the player makes to cause the branching are not significant and interesting, you hold that up as an example of a bad implementation of branching.

the clearest one is the iconic one of a fork in the path. First of all, the choice is not significant as without any context to the choice it becomes an arbitrary choice. It is also not interesting because the choice is between one seemingly identical path and another.

One of the best example I have had of branching story lines is Freespace 2. In this game, as long as you survived (didn't get killed) you could proceed to the next level. However, if you fail to achieve the goals many missions (and some are more significant than others), then you will be presented with a change in the plot line of the game. You might find that you have to fight enemies in different systems, or in greater numbers, or even have completely different mission altogether. But, if you were really good and were able to succeed at many of the missions and complete lots of the secondary objectives, then you can be rewarded with access to new mission or even (if you succeed at these too) new weapons and ships.

Here the choices (success or failure of the missions) are significant because it is a player choice/ability that chooses the branch and they are interesting because they have an impact on the experience the player has with the game.