In writing, there is a cherished and oft-used foreshadowing device known as "Chekhov's Gun." Basically, if there's a gun (or anything else really interesting) sitting around in the beginning, it HAS to fire or be otherwise used by the end.
Perhaps nowhere is this better used than in the marvelous world of science fiction: A vat of acid, a space powerloader, a prototype arc reactor ... sci-fi loves introducing some seemingly meaningless artifact, then unleashing it during the big climax.
Yet sometimes, we can't shake the feelings that a "Chekhov's Gun" is firing simply for the sake of firing, but is really unnecessary to the storyline. Looking over some of our favorite sci-fi and fantasy films, we found a handful of "powerful" artifacts that actually don't help anyone at all.
If we missed something on any of these, like maybe a deleted scene that explains everything, let us know, because we still have fond affections for all these artifacts.
And share your favorite sci-fi artifacts that ultimately proved pointless!