You could change the ending of Fight Club to match the book but I think that would piss people off.

From what I remember, only one scene of the book didn’t make the film, the narrator and Tyler original meet on a beach. Also, a running theme is that the narrator can’t quite remember how to make home made explosives, he keeps getting the recipe wrong.

So at the end, when they’re going to blow up the credit card headquarters, nothing happens because the explosives are dud.