Especially these days, James Cameron is a near-household name. With Titanic just rereleased in 3D, and Avatar still fresh in viewers’ minds, he’s one of the biggest box office draws of the 21st century. And with the announced Avatar sequels going into pre-production, one has to look at Cameron’s earlier sequels, which hold a prestige of their own.

In the early 1980’s, James Cameron was still a struggling director, only having worked behind the camera on Piranha II: The Spawning. But he’d had an idea, culled from a fever dream he had during the making of The Spawning, about a metal man, a robot. And this concept spun into The Terminator, his first feature film hit. He was set to start production with star Arnold Schwarzenegger, but the actor was away filming the second Conan film. In the mean time, James took two screenwriting jobs, leading to the first two “sequels” : Aliens and Rambo: First Blood Part II.

Aliens was the sequel to Ridley Scott’s Alien, a highly-acclaimed science fiction horror film. It was a nearly-impossible act to follow, but Cameron gave it a try anyways. In the end, both Aliens and it’s prequel earned several awards, and in a parallel, each one Best Science Fiction Film and Best Direction at the Saturn Awards in their respective years. How was it so successful?

Aliens follows Ellen Ripley, the lone survivor of Alien. 57 years after the original, Ripley is woken up from hypersleep and finds that her employers don’t believe her story about the alien, and the planet on which the alien was discovered is now a colony. Contact with the colony was lost, so she begrudgingly joins a team of space marines and a corporate weasel to the site to investigate. Judging by the title, the rest of the plot isn’t too difficult to figure out. They encounter the alien, actually dozens of them. That simple change to the formula of the original is key to Cameron’s sequel synthesis, but the other examples should be explained first.

Rambo: First Blood Part II is the only of the sequels that Cameron didn’t direct. He was listed in the end credits as one of the writers, along with Sylvester Stallone, who drastically altered the original script. It’s even been suggested that director George P. Cosmatos was only on set in a supervisory capacity, and that Stallone did the lion’s share of the directing. It was clearly Stallone’s baby, and one of his signature franchises, along with Rocky, so it makes sense that he’d tailor it as he saw fit. Looking at Cameron’s original script, titled First Blood II: The Mission, does bare similarities to the end product, namely the second half, where Rambo heads to Vietnam to rescue POW’s, only to be abandoned by underhanded government types. One key difference is the addition of a male sidekick of sorts, to help Rambo on his mission. Cameron’s story effectively carried the characterization and depth of John Rambo from First Blood and expanded upon it. It’s a tense action-adventure, uniquely Cameron in style, with fantastic set pieces and well-developed characters. In the end, Cameron noted that a fair portion of his action sequences were maintained on screen, but everything else was tenuously adapted. Stallone at one point told Cameron he wished they would’ve stuck to the original script instead of forcing politics into it.

An interesting parallel between his two early scripts is Vietnam. Most obviously First Blood II is set there, but Cameron has admitted that Aliens was based somewhat on the Vietnam War, in that a technologically advanced force was going up against a much less outfitted force, and losing terribly and unexpectedly. But Cameron wasn’t interested in politics. Both scripts weren’t about war, even though that was all around the characters, but about the characters, the soldiers themselves. That personal attachment elevated the works from the standard war movie, like any of the rabble of First Blood II copy-cats, like Chuck Norris’ Missing in Action.

That leaves Terminator 2: Judgment Day as the final Cameron sequel (for now). By all counts it was an unprecedented success. It appears on countless lists as one of the greatest science fiction and action films of all time, and most would claim it’s better than its predecessor. It featured ground-breaking and still-impressive special effects, a box office smash. It picks up the story from The Terminator eleven years later (even though the movies were only released seven years apart), following John Connor as a teenager, now rebelling against his step-parents. Meanwhile, Sarah Connor is in a mental hospital, committed after nobody believed her story about a killer robot and a hero from the future. But as is par for the course, two characters come from the future to fight for the fate of the human resistance. The twist this time is that both characters are terminators, different models, and one has been reprogrammed to protect John Connor. Sarah, John, and the T-800 attempt to prevent judgment day, the beginning of the nuclear holocaust, the beginning of the war of the machines.

All these films were successes, at least financially. The features directed by Cameron were critical successes as well. This seems to suggest that Cameron is one of the rare filmmakers that understands how to craft a quality, worthy sequel. That is, after all, one of Hollywood’s great mysteries: how to follow-up a great film with something on par. There must be some formula to it, and closer inspection reveals that there is.

Upping the ante and changing the game. Those are the main tenets. The stakes have to be raised, and the genre has to be adjusted. In any given original film, the audience comes to know characters and how they react to a given situation, to the plot. This leads a lot of filmmakers to almost remake the original film for the sequel, considering the audience liked it the first time around. See Ghostbusters II and Die Hard 2: Die Harder for perfect examples of the reheated sequel. Both are entertaining, but not nearly as good as their respective predecessors. It’s because the audience isn’t seeing anything new, and they’re literally seeing the same characters react to nearly identical situations, so there’s nothing fresh about it.

So the first step is to up the ante, as it were. The central conflict has to be ratcheted up, so that something more is learned about the characters. In Alien, the crew of the Nostromo had to contend with a single creature. Ripley ended up surviving due to her courage, but she never really directly fought the alien. She opened the cargo hatch, then fired up the engines to kill it. So how does a filmmaker plus that? They add more aliens. Notice the sequel is ingeniously titled Aliens. Cameron put that same character, that the audience already watched and grew to know, and put her in a more dangerous, though similar, situation. It’s an effective continuation of the character’s development, because they’ve already experienced the previous film, so they’d be more prepared the second time around. That escalation is necessary to make sure they’re not certain they’ll succeed or survive. Similarly, in Rambo’s story, he’s taken from the relative seclusion of the Washington woods of First Blood to Vietnam, the heart of darkness for the hero. Instead of facing some small-town police, he takes on a nearly endless swarm of Russian and Vietnamese soldiers. No matter how well-trained Rambo was, that’s still a tremendous jump in odds. And again, the ante has been upped. That’s not even considering that Rambo’s mission involves the lives of other people. In First Blood, Rambo was out to survive, spurred by haunting memories of Vietnam. But now, he not only has to face the same jungles that scarred him, but save some prisoners as well, prisoners that he empathizes with. The conflict rises. That leaves Terminator 2, which again is a simple algebraic change. Instead of one terminator, there are now two. And not just the same two, but an advanced prototype as well, that has a whole new set of rules and abilities. Interestingly, a lot of the sequences in T2 are almost direct references to the original, and yet they’ve been imbued with fresh suspense and action. The second addition in T2 is the addition of a second mission: actively trying to prevent judgment day. In the original, Sarah Connor and Kyle Reese were essentially the antagonists, trying to prevent the Terminator from killing Sarah. In the sequel, there’s still the element of trying to prevent John Connor from leading the resistance, but with an added bit of protagonism, trying to stop the condemning future from happening all together. It’s another ratchet of conflict, of suspense, to keep the characters dynamic and the plot on that line between familiar and fresh. It’s the original, plus more.

Now that the stakes have been raised, there’s still something missing. Take Die Hard With a Vengeance. It does up the ante, opening up the contained action and spreading John McClane and co. across New York City, racing to save millions of lives from a series of bombs. It makes for thrilling action, but it’s not the perfect sequel. Namely, at the end of the day, it’s still John McClane shooting at robbers posing as terrorists. It’s raw action, and while that’s certainly exciting, after a few retreads, it wears thin. It needs another change to the formula, a change in the game: a genre-shift.

Alien was horror. Aliens was horror-action. Terminator was sci-fi horror. Terminator 2 was sci-fi action. First Blood was an action-thriller, with some psychological elements. First Blood Part II was pure action. Note that the genre is never changed, but its specialization shifted. This, in essence, provides for the stakes to be raised and the character to again face formidable odds, as they’re also in a new element. Ripley had to learn how to use guns, and basically become a space marine to combat the new threat. Rambo went from inner torment to reliving his war days, and becoming the perfect killing machine again. The characters react to the genre shift, offering something new.

In the big picture of things, these two changes make a quality sequel, at least by Cameron logic. But these are overly basic, as surely there are examples of sequels that follow both these rules and still are subpar. However, there are a few sub-rules within the sequels that Cameron returns to in each example.

First, the main character must overcome a prejudice, handicap, or problem from the first film. In Alien, the lone android onboard the Nostromo goes berserk. In Aliens, Ripley doesn’t trust androids because of this, but in the end, she learns to respect Bishop, the lone android among the characters. In The Terminator, Sarah Connor is pursued relentlessly by the titular cybernetic organism. In T2, when an identical robot arrives to help, she doesn’t trust it at all. But by the end, she’s overcome her prejudice and learns to respect the terminator. In First Blood Part II, Rambo must overcome his post-traumatic stress as he actually returns to Vietnam, fighting again. It’s a key way to link the original film but also push the character forward. The audience wants familiarity with the first film, but also something new. This is a simple way to connect the two.

The other two sub-rules deal with the circumstances at the beginning of a sequel. A sequel by its definition is a continuation of a character’s story. And as pointed out earlier, the main character must continue developing in different ways and in different situations. Unless a sequel is a direct sequel, like Back to the Future Part II or Part III, there will have been some time in between the original film and the continuation. And that has to be dealt with. Obviously a lot has happened. Or at least it should. If you look at Aliens, Ripley has woken up from a 57-year hypersleep. In a sense, Cameron put her in the same spot as the audience, dropped into a familiar universe many years later, with no clue as to what’s happened in the meantime. But significant events have indeed happened, like the planet LV-426 has been colonized. This sets up the events of the film to come, while also filling in what’s changed since the last movie. In First Blood Part II, Rambo has paid for his actions in First Blood, and is in a prison camp, smashing rocks all day long. Colonel Trautman arrives and tells him that the government believes there are still some POW’s in Vietnam, so he must take photographic evidence of them. Politcally, things changed. For Rambo, things changed. In T2, Sarah Connor is in a mental hospital because of her account of the original terminator. In the meantime she’s had a son and trained to become a warrior. Circumstances have changed. Notice that all the characters have, in some way, been cut off from society for a while. Ripley was asleep, Rambo was in prison, and Sarah was in an institution. This isn’t an essential ingredient, but an interesting Cameron common thread.

This idea of changing circumstances logically may seem obvious, but a few counter examples may prove otherwise. Take Ghostbusters II. It starts with the three main scientists doing something other than ghostbusting, trying to make a living, when Dana Barrett visits them and asks for help with paranormal activity around her. They then investigate and find that New York City needs Ghostbusters, so they reform the company. It’s a suitable plot, but it’s a rehash of the original and it completely undoes any momentum started by the original. Instead of showing them in business, as the end of the original implied, the sequel tells that they were sued by the city (and then some) out of business because apparently nobody remembered the 100-foot marshmallow man. It leaves the heroes precisely back where they started the first time around, allowing them to go through the same motions. It doesn’t make for an interesting story because it’s been told before and the characters are used to it by now. Similarly, Die Hard With a Vengeance starts with McClane on a day off, in bad shape and separated from his wife, just trying to get by. He actually starts out a little worse than in Die Hard, now an alcoholic. But in Die Hard 2, he saves his wife again and they presumably lived happily ever after. But instead, the filmmakers took it all away from McClane and then some, leaving him in the same sort of hole he was in during the original, and again, he’s covering familiar ground.

After that tangent, all it leaves is the last sub-rule. A sequel must function on its own two-feet as a solid film, without the original for back-up. However it’s a delicate balance between making sure the film references the original, but not enough to make the sequel confusing. Aliens easily functions on its own as a story. It’s structured so that the required information from the original, that Ripley and co. found the alien on LV-426 and was the only survivor, is explained. Therefore the suspense for the sequel in itself lies in the waiting for the creature to appear. Likewise T2 can be watched on its own and thoroughly enjoyed because it explains everything the audience would need to know. Viewers of the original will likely enjoy it more, but there’s nothing left too open in the sequel itself. First Blood II, especially the version that reached the screen, doesn’t require a viewing of First Blood. We learn that Rambo was a war hero that snapped, was put in prison, and now his expertise in Vietnam makes him the best candidate to rescue POW’s. Compare this to Back to the Future Part II, which picks up immediately after the first, and even takes place largely during the events of the first. Granted, a viewer could catch up with events and characters as it progresses, but it relies heavily on a knowledge of the first, especially because it intertwines with the first. It’s still enjoyable on its own, but it really requires having seen the first to truly be appreciated. As such it only really appeals to those who are familiar with the first. The same can be said for Part III, which while entertaining on its own, makes much more sense when viewed after the first two installments. A sequel must stand on its own. The Indiana Jones series supports this idea, as each film is episodic, and largely unrelated to the others.

“I think sequels should be earned,” said screenwriter, director, and producer Jay Roach. A growing trend in Hollywood is to write sequels before the original film even hits theaters. The common concept of sequels is that they’re purely commercial, made only for the money and because of the reputation of the original. That’s certainly accurate, at least in some degree, but that doesn’t mean the audience should be treated to a subpar film because of it. Instead of cranking out a nearly-identical sequel, as Hollywood is so wont to do, there ought to be some thought and craftsmanship put into them. James Cameron’s trilogy of sequels illustrates that craftsmanship to a tee.