TV Tropes is a site (not just limited to TV shows) that lists the many tropes we encounter over and over in fiction. In the Action and Adventure category, here are a few examples: Action Dress Rip, Break Out the Museum Piece, Ferris Wheel of Doom, Last Breath Bullet, and Sleight of Tongue. There are dozens and dozens of tropes (with examples) from all kinds of genres.
I loved this quote, from the entry entitled “Applied Phlebotinum,” which is defined as “the magical substance that may be rubbed on almost anything to cause an effect needed by a plot.”
If the phlebotinum in question is something that needs to be mined you may well be dealing with the element Unobtainium.