When the sequel pool has dried up and it's too soon for a reboot, the go-to trick to extend a movie franchise is a prequel. It's a money man's dream - an origin story for a beloved character shedding light on familiar events allows a studio to take a property in a new direction without having to make any drastic creative decisions.
Got a troublesome actor? Recast them with a younger alternative. Worried about the film making money? You can just pander to the same people who loved what came before. Not got an idea for a plot? Don't worry - having the original movie as an end point excuses a lack of narrative purpose. Perfect!
Of course, because they're rarely born from a genuinely creative place, most prequels fail to escape the original's shadow. Every element of their being is down to a previous success, and more often than not they're happy to bask in that familiarity. By far the most sinful example is The Thing, which purported to show what happened at the Norwegian camp briefly visited in John Carpenter's classic, but wound up being little more than a retread of the original's plot.
Oh, there's exceptions, but they really are special cases. Better Call Saul is already a solid example of how to get the balance of pleasing fans and providing a new experience - featuring cameos and feeling very much in the same world, while still charging forward with a new story - but that that's remarkable highlights how far off the mark most precursors are. And, at the end of the day, even good prequels can make that biggest of errors - plot holes. The originals set a timeline and hint a backstory, then these earlier stories barge in and mess it all up.
Here nine crazy examples of prequels that unwittingly made massive continuity errors.