Ive died in dreams....quite a few times, i even got sawed in half once. that was pretty fucked up. i felt no pain and just thought wtf was going on, then another dream started.

anyways if it was true then not many people would survive anything at all.

e.g.you get shot and think oh shit im dead now, so you die? no, you dont, the only reason ud die is if you suffered from some sort of serious injury and it either couldnt be or wasnt treated in time.

e.g.2.you fall from a building, right before u hit the floor, u truly believe your about to die.does that mean you WILL die, once again, no it doesnt. just as if in a dream you truly believe ull die, but you dont, and if in a dream u truly believed ud die and u did, then it'd also happen in reality. but it doesnt, so as some others have said, the only reason you'd die for real if in a dream, would be due to a serious weak heart problem, or maybe even some other sort of thing, like a virus thats slowly been eating away at you and finally finishes its business as you slept one night.