multiple story lines

The easiest way I would do it (just me not neccesarily the best way to do it). Is depending on what you want to be the trigger for different story lines, have a variable or switch for them. then depending on which of those switches are on, or what number the variable is at. You can go through certain quests and certain cutscenes come up. just make sure that before you show the quest it says, needed (blah var) or (blah Switch = on)
if you don't understand it i'll make a demo. Just e-mail me for a faster response though
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