A terrific performance or two can bolster an already good movie and elevate it to true greatness, but the opposite is also true: poor acting can spectacularly derail a film and ensure it fails to live up to the greatness of its script, direction and the rest of its cast.
These 12 movies, most of them broadly acclaimed for the quality of their production, their entertainment value and their ambition, are nevertheless hamstrung by wonky, ill-advised performances that severely damage the whole.
With stronger casting, these films could've been so much better, rather than forcing audiences to suffer through performances that are distracting at best if not downright laughable at worst. For most of these movies, the qualifier, "They're good, but..." firmly applies.
Whether you can still appreciate the film or not, these movies all fell depressingly short of greatness due to poor casting decisions and actors who fundamentally couldn't meet the needs of the material...