Several weeks back, when I first saw the trailer for the Harrison Ford thriller “Firewall,” I thought to myself, “Wait a minute?haven’t I seen this movie 100 times before? And wasn’t Harrison Ford in every single one of them?”

These days, I get that feeling every couple weeks during my weekly jaunts to the Cineplex. It’s as if we’re in a perpetual state of dj vu. You’re never going to believe this, but next month, Denzel Washington and Bruce Willis both play cops in big-budget crime thrillers.

No, I’m serious.

A few weeks later, Sharon Stone plays legendary femme fatale Catherine Trammell in “Basic Instinct 2,” 14 years after the original came out (and sucked, by the way). And not long after that inevitable disaster, Michael Douglas plays a desperate man on the run from justice and/or working against the clock in “The Sentinel.”

Just like he did in “Disclosure,” “The Game,” “A Perfect Murder,” “Basic Instinct,” “The China Syndrome,” “Don’t Say a Word,” “Fatal Attraction,” “Black Rain,” etc.

Also, to make matters worse, in “The Sentinel,” Jack Ba-um, I mean, Kiefer Sutherland plays a hard-nosed FBI agent trying to uncover an international conspiracy. Not that we’ve ever seen that before.

And so I began thinking to myself?how do they come up with this stuff? How do they get away with making the same movie over and over again? Surely, it can’t be a system operated by living, breathing, thinking humans. No, the cold machinery of Hollywood couldn’t be coordinated by mere humans. It must be governed by something more, something ruthlessly efficient?

The only logical conclusion I can come to is a Random Movie Generator. Really, it’s quite simple and makes perfect sense. A Random Movie Generator (or RMG) is a machine that, on command, spits out movie ideas destined for box-office gold. Kind of like that “South Park” episode in which Cartman dresses up like the cardboard robot and spits out thousands of movie ideas, all involving Adam Sandler.

Ha, ha, ha?oh, that Cartman.

Let’s just go with a little demonstration so that you can all learn how this works and can someday run movie studios of your own.

First you’ve got to find your protagonist, preferably with as much testosterone as possible, as per Hollywood tradition:

A) Bruce Willis as a grizzled cop who takes the law into his own hands.

B) Denzel Washington as a wily, cynical cop who has seen it all and who has too much intuition for his own good.

C) Michael Douglas or Harrison Ford as a wealthy businessman who gets his world turned upside down.

D) Tom Cruise as an overly emotional loner with paternal issues who has to seek out revenge on the evildoers who stole his (insert emotional attachment here).

E) Angelina Jolie as a bad-ass crime fighter who runs around in skimpy outfits and shoots a lot of people, all with a wink and a smile and without even smudging her mascara.

F) Arnold Schwarzenegger as a guy who likes to blow lots of stuff up.

G) Will Smith as a wisecracking tough guy with a chip on his shoulder. He will speak two lines of dialogue and two lines of dialogue only:

1. “I have got to get me one of these!”

2. “Ah, hell no!”

Now that we’ve got that out of the way, we’ve got to have a plot. No need for creativity here. These are very straightforward:

A) A mad scientist vows to realize an “unimaginable evil” that will force our society to crumble to its very foundation.

B) An innocent man is framed for a crime he didn’t commit and is forced to become a fugitive from justice in order to clear his name.

C) International terrorists-preferably with dark skin, so as to reinforce the comfortable xenophobia of White America-take over a military compound and threaten to start World War III unless 19 hostages are freed and given, like, a zillion dollars or something.

D) A criminal mastermind holds up a bank and/or kidnaps the president of the United States and engages in a battle of wits-not to mention a lot of witty repartee-with a veteran cop who has nothing to lose.

E) An innocent woman (preferably Julia Roberts?in fact, it’s always Julia Roberts) gets unwittingly caught up in a sinister plan to retrieve secret military documents and assassinate a foreign prime minister.

F) Some element of modern technology develops a mind of its own, and it’s going to take a team of hot young action heroes to take it down!

Finally, and perhaps most importantly, are the supporting characters, typically used to provide comic relief, a romantic angle or both. One should include as many of these characters as possible and preferably all of them.

A) Sharon Stone as a sultry seductress with an agenda of her own.

B) Vince Vaughn as the high-strung “best friend” who gets the hero into trouble.

C) Cedric the Entertainer as a generally annoying guy who delivers bad jokes and who at one point will start to break dance for no reason whatsoever.

D) Al Pacino and/or Samuel L. Jackson as tough guys who show up every 20 minutes solely to shout obscenities and flaunt their bad-assedness.

E) Christopher Walken. Don’t ask questions.

If you must, you could go for the jugular and cast Tom Hanks as a mentally challenged, gay, foreign military police officer/astronaut stuck on an abandoned island, dying of AIDS and living across the street from Meg Ryan.

Finally, I can’t emphasize this enough: Morgan Freeman is your narrator. Again, don’t ask questions.

And that’s how you make a movie.