Originally Posted by Adrir
I don't think event & trigger based gameplay is strictly branched because the triggers and events can occur, in theory, in significantly different orders. Although it can make the story more difficult to follow.
That's probably why so many game stories are linear. People are afraid they'd be too difficult to follow. It really depends how it was pulled off. To do it well, you would need a good narrative designer who can make the events make sense no matter which order they are in, and perhaps add a significance to each different order.
Game flow has the ability to effect plot flow. It probably should affect plot flow. But it doesn't in a lot of games.
For example, the Godfather Blackhand edition, it has a similar sandbox play where you can do anything. However a certain spot will be marked with either a blue dot or blue x, and going to that spot will activate a main story event. It doesn't matter how many stores you take over, people you kill, cars you steal, mob fights you instigate, banks you rob or strippers you hit on in between. The main story is unaffected. No matter what you do, John Waltz will still wake up to find Khartoum's head in his bed. This event will occur right after Michael is safely driven to his ship. It will occur before the main character moves to live in with his sweetheart, Frankie. Again, what you do in between doesn't change this. Though the side stories are near endless, the main story is unaffected.
Writing for games is different than books and films because it is the designers'/writers' duty to figure out how player interaction will immerse the player into the story and whether or not the player has the power to alter the events that occur. In many games, the player doesn't really affect the story, the interaction only results in the player being more immersed into it. That said, many of the methods films and books use to tell stories can be effectively put into a game. Flashbacks and such are among these. Again, a lot rests on how it is done, which details are emphasized in what way, etc.