Now, videogame sequels are a different kettle of fish. But then, the story does tend to take second place to blowing stuff up.

Spoiler warning: I'll be going into quite a lot of detail about a number of films in this post. Basically, as soon as you see that film's title mentioned, bear in mind that I might well reveal key plot points. Fortunately, most of the films I'll be talking about either don't have major plot twists, or they really, really suck. Be warned, though.

It wasn't that long ago that the cinema was dominated by major trilogies of films. The Lord of the Rings movies stormed the box office throughout the first few years of the new millennium, around the same time as the Matrix films, and action series like Die Hard and Terminator have had new instalments reasonably recently. In some cases, these are pretty good; in many more, they just suck. So why the variability?

One of the major reasons has to be whether the original film was meant to be part of a trilogy. In the case of The Lord of the Rings, there was already a three-part narrative structure in the books, and although it didn't lend itself perfectly to film adaptation (interleaving the stories in The Two Towers was the most obvious structural change in the films), the story was so clearly mapped out that Peter Jackson simply didn't have the option to do much in the way of sweeping changes. Or take Kill Bill, which was, to all intents and purposes, a single film cut in half because audiences don't like sitting still for four hours. The sequel works because it continues precisely the same story.

In contrast to this, take a look at The Matrix. The Wachowski brothers claim to have planned all three Matrix films ahead of time, but production didn't go ahead on the second two until the first one had been a popular and critical success. That meant that The Matrix had to stand by itself as a coherent story without its sequels, making it that much harder to blend in new elements later on. It's worth mentioning that having no overarching structure isn't necessarily a bad thing, as long as the later films are sufficiently different - for example, Terminator 2 is an excellent film, despite being a sequel, because it tells a new story in the same universe.

Another of the keys to successfully pulling off a sequel is not to go overboard with whatever made the original film a success. The Die Hard films tend to work because they don't change very much - John McClane gets into a bad situation, fights against overwhelming odds, and shows just how much of a maverick he is by blowing up lots of stuff and swearing at authority figures. If a Die Hard film tried to push the formula too far — made McClane save the entire world from a terrorist ring who had kidnapped his eight-year-old niece, for example, à la Commando — the audience would reject it because it simply doesn't fit the formula, and pushes McClane's character past what we expect of him.

As before (and, sadly, somewhat typically), the way not to do it is typified by the Matrix sequels. It happens with a lot of elements (Neo's somehow able to control machines in the real world thanks to some bizarre explanation that makes midichlorians look reasonable? Seriously?), but the most egregious is the Christ analogy. These were present in The Matrix, but they were treated a lot more subtly — Neo dies, only to come back with considerably more power, and proves himself to be the saviour of the humans. It's not a hugely obvious parallel to draw, and it won't do more than just gain a bit of emotional resonance with the audience.

In The Matrix Revolutions, however, the analogy is drawn well past breaking point. By this time, we've met the Matrix's "father", who gave rise to the One, we've seen that he is aware of everything that happens throughout the Matrix, and we've seen Neo die again (because the first time clearly wasn't quite enough). And at that point, a gigantic golden cross explodes out of his chest.

Subtle.

In the end, the audience gets incredibly tired of the scriptwriters hammering the same bits of symbolism into their heads again and again, and it detracts from the film. Coming after two entire films of bad philosophy and insufficiently awesome fight scenes, it's just too much to bear.

It's not just the characters that have to be maintained throughout sequels — the entire concept of the films must be preserved, too. This is related to my first point (because films planned as trilogies from the word go have an overarching structure anyway, and therefore keep a consistent set of underlying assumptions), but films without this structure are perfectly capable of maintaining ideas. The Batman films, throughout their many variations, always manage to preserve the basics — Batman is a secretive crime fighter, who always tries to do the right thing, and doesn't kill if it can be avoided, while Gotham City is a mob-run den of villainy.

On the other end of the scale, we have Terminator 3. What made Terminator 2 so good was that, despite the sense of the weight of the future, there was always hope, and a possibility that maybe the future war could indeed be averted. All three films constantly mentioned the "no fate but what we make for ourselves" slogan. And then Terminator 3, for no apparent reason other than to get the audience really depressed (and, of course, set up another sequel in the future), made the war start anyway. All that hope, the tiny spark that meant that maybe that slogan might just be true after all, gets crushed for the sake of the effects department getting to show off their ability to do mushroom clouds. The film itself isn't that bad, but as part of the Terminator series, it's about as awful as it could get.

One more key to making a successful sequel: know when to stop. Alien was great, Aliens was good, and Alien³...wasn't. At all. I haven't even seen Alien: Resurrection, mainly because the very idea of it is enough to scare me off. Toy Story 2, contrary to expectations, was really good, but I'm holding out precisely no hope for Toy Story 3. And the less said about the apparently endless Lion King straight-to-video sequels, the better. Sadly, as long as someone thinks that the franchise can be milked just that little bit further, the never-ending sequel factory will continue churning out some of the worst films ever to grace a cinema screen.

Gives me something to complain about, though...