Lights! Cameras! And (most importantly) Action!
If you look at the list of top movie money-makers, you probably won't be surprised to note that most of them are action-adventures. We do love our action, don't we? Let there be fist fights, sword fights, gun fights, huge explosions, and swinging from ropes, in any combination, and we're there. Of course, there have also been action movies with most if not all of these elements that have flopped miserably. Not a sign of the audience turning from the genre, the flops were simply bad movies. The greatest fights, stunts and explosions in film history can't save a bad movie.
What Makes an Action-Adventure a Good Movie?
What are the elements of a good action movie? Frankly, complex characters and great acting are not required. But there are two basic requirements: the hero has to be the underdog, and the hero has to have a compelling need to accomplish his goals.
The Hero as Underdog element is best illustrated by (and explains the massive popularity of) the Die Hard movies. In these, New York cop John McClane (Bruce Willis) begins as an unarmed man or armed with at most a pistol, up against a legion of highly trained, heavily armed, and completely ruthless villains.
If the hero is a martial arts expert, numbers alone won't make him the underdog. The scene of him taking on a few score random street thugs is going to be an appetizer early in the movie; for the big battle before the closing credits, the hero will face off with one or more martial artists at least as skilled as he is.
The underdog theme is shown again in the first two Terminator movies. In the original Terminator, two unarmed humans are up against an unstoppable remorseless killing machine, played by Arnold Schwarzenegger. Come time for the sequel, Terminator 2: Judgment Day, and Schwarzenegger is now a big star and cast as the hero. This time he's another version of that unstoppable killing machine, reprogrammed as a young boy's protector. The lengths the writers had to go to in order to make Schwarzenegger appear to be an underdog illustrates just how important this element is to the success of the story.
The importance of the hero's success is also critical. Again, the Die Hard series gets this right, the well-known "That's my wife in there!" motivation.
The hero is not scaling that mountain "because it is there", but because it's the evil genius's secret lair, or whatever. The hero must save the girl, save the family, save the nation, or save the world.
For an example of the need for real motivation, one need look no further than the movie that killed CarolCo, 1995's mega-flop Cutthroat Island, which earned back a mere tenth of its production costs. On paper, this movie had a lot going for it, attractive stars, great locations, and some of the most elaborate action sequences ever filmed.
Unfortunately, the story was about a young female pirate captain who was in search of a treasure because.... well, because she wanted it, that's all.
And a note to the geniuses who penned the script and the suits who greenlighted it. About that 'treasure map tattooed on the top of the head' thing. If you are seriously going to write a story that calls for your heroine to scalp her dead father, you'd better give her a mighty darn good and noble reason for needing that treasure, or guess what?
Your audience won't like her.
So there you have it. Hero as underdog and hero with compelling need to achieve goal. Next time you watch an action-adventure movie, see how well the movie accomplishes these two objectives, and how that correlates to how much you enjoyed the movie.
The rest is gravy.