For anyone who skipped that day in Latin class, this phrase means “God out of the Machine.” In screenwriting, it’s a pejorative term that describes when you get your protagonist into a big jam and then don’t know how he can escape, so you bail him out with some convenient contrivance, such as an actual act of God, or the help of some other character who shows up out of the blue, or the sudden introduction of a new ability or some other unexpected bit of perfectly-timed information, or the hero’s sudden realization that, “Hey, someone must have accidentally dropped a gun in my jacket pocket, so I’ll just use that to shoot the bad guy and get away!” If you do that, Robert McKee will find you and will beat you over the head with a lead pipe that he will just happen to find lying at his feet as he sneaks up behind you while you are reading a screenwriting blog.
Remember in “The Abyss” when Ed Harris makes that deep dive, knowing that there will not be enough time for him to make it back up to the surface alive, but then the underwater alien dudes have inexplicably built some kind of glowing dome on the sea floor that contains breathable oxygen, even though they don’t need to breathe oxygen themselves? Yeah, that’s a good example. Or how about at the end of “Independence Day” when Jeff Goldblum somehow manages to upload a computer virus to the alien ship that disables their defense systems? How nice of the aliens to give him their IP address and what luck that they happened to be running Windows 95 (even though Goldblum used his handy Macintosh PowerBook to upload the virus remotely). In “Raiders of the Lost Ark,” it’s actually God who kills the bad guys when they open the Ark, which makes things much easier for smarmy movie critics like me who are just waiting for this kind of thing to happen.
The good news is that problems like these are easy to avoid. Audiences will gladly forgive you for instilling your hero with some extreme ability or even a superhuman power, as long as you set it up in advance. If there are creatures living in a big oxygen-filled dome at the bottom of the sea, then you could show a small version of that kind of dome at the beginning, or even have a crazy sailor talk about falling overboard and then breathing from a glowing bowl of oxygen until he reached the surface. If Jeff Goldblum needs to send a virus to the alien computers, then you could set that up by having the aliens use a technology that we haven’t yet mastered on earth –but which Goldblum can then figure out– to send a virus to our own computers at the Pentagon. At least in “Raiders,” they set up the Ark killing people by letting us know beforehand that Indy believed in that story.
There are plenty of great examples in movies of how to set up this kind of thing so that the audience won’t groan when the hero miraculously escapes at the end. Just about every movie in the James Bond series begins with Q showing James some awesome new weapons, and then ends with James using one of those awesome new weapons to get out of an impossible situation. The guys in “O Brother, Where Art Thou?” were rescued by a catastrophic flood, but we don’t mind because the wise man foretold this. And we knew that Joaquin Phoenix would be able to repel an alien invasion with a baseball bat because his dead mother told him to “swing away.” Sorry, I couldn’t resist sneaking in just one sarcastic example there. But I know that my audience will accept this because I set it up earlier by describing myself as “smarmy.”