If you knew how to write a script, they'd probably reject you out of hand. Trust me on this, I've been watching their movies for years.
You also might be thinking that there is no such thing as the Sci-Fi Channel anymore. That's true, they changed their name. Now it's SyFy (SeeFee*) but I'm not about to go around writing, "SeeFee this," and, "SeeFee that." I note that it's SeeFee when in writing only, whenever it is spoken you can hear the c in "Sci" not to mention the fact that it ends in an "i" rather than a "y". So in spoken word it's still Sci-Fi, and as long as it remains such I'm going to write it the way that it is spoken which, as of today, continues to be Sci-Fi.
Now that we've gotten the basics out of the way, provided you are not a writer at some point in your life you will be approached to write a movie for the Sci-Fi Channel.
First off, my advice is to take the job because otherwise it will go to someone else and, while you might think that no one could be less qualified, you'd be wrong. They will find someone less qualified than you if you turn them down.
Thus I present some general guidelines. Not rules so much as pointers.
First off, know the genre.
For example, give or take half the time the movie you'll be called on to write will be a creature movie. Bad creature movies come in two flavors. They follow in the footsteps of either Jaws (town based) or Aliens (isolated group based.) Knowing the genre can allow you play with the genre, as was done by the makers of such not-for-Sci-Fi movies as Bats and AVPII (movie, not the game; game was better), but you have to know the rules before you start breaking them. You're writing (bad) hiaku here, not (bad) free-verse.**
Bats played with the rules by having the one that survived, digging itself out of the ground to ominous music, be immediately run over by the Jeep the human survivors were leaving in, the music abruptly switching to the much more upbeat music those in the Jeep were listening to.
AVPII played with the rules by following them exactly, but setting you up to think it was a town based creature movie when it actually turned out to be an isolated group of survivors movie.
Once you know the rules, you can deviate from them, provided that you do so in a way that doesn't leave the audience with the feeling that you don't know what you're doing. That said, just as you should keep the genre in mind, so too should you keep the audience in mind.
People do not tune in for a movie they know will be bad so that you can intentionally depress them in an attempt to get across your philosophical or political message. People do not go to a James Bond film so that at the end of the movie the villain can win and Bond can be left a broken man wandering through the shambles that once were London. It doesn't work that way. What you're making for the Sci-Fi Channel will never rise to the level of James Bond. Even if your script is perfect the acting and effects will ensure that the overall movie sucks like chest wound.
If you end the movie with, "Rocks fall, everyone dies," the audience will feel that you betrayed them and they will not be wrong to feel that way. By deciding to make a bad movie for the Sci-Fi Channel you entered into a covenant with the eventual audience. Part of your end of the bargain was an ending in which the good guys don't lose. The absurd ancient aliens theory is not disproved, the world does not end, the creatures don't swarm across the face of the earth bringing an end to civilization (yet, do recall that one always survives) and in general things don't work out crappily.
If you break that covenant then you become the six fingered man, "I just sucked two hours of your life away. I might one day go as high as 24 but I really don't know what that would do to you. So, let's just start with what we have. What did this do to you? Tell me. And remember, this is for posterity so... be honest. How do you feel?"
So, those are the two big things: Know the genre; know the audience. Betray neither. Everything after that gets into the nitty gritty.
Sometimes you feel like you need to include a character arc, in fact that is most often the case. I'm not going to recommend against that, but I am going to make one recommendation: don't have your central character be a seemingly irredeemable asshole with with no good qualities. Even if you brilliantly draw out the good in them over the course of the movie it won't matter because that sound you heard early on was the entire audience changing the channel to watch something else.
There is a reason that Iron Man, the story of an asshole, begins with Tony Stark getting his ass kicked and taken hostage and then flashes back to him being an asshole. The audience is hooked by the hostage taking and that carries them through the asshole flashback until Tony is in the cave at which point we get to see him not being an asshole. Told in strictly linear order the movie likely would have failed. Your movie will not be as good as the Marvel Cinematic Universe. Again, even if your script is perfect the acting and the effects will make it a bad movie, so shooting for something that is difficult at best in a good movie that's well funded is probably shooting too far.
Have sympathetic characters.
Have a sense of scale.
I mean this on multiple levels. It's not just the standard thing about people having no sense of scale with respect to the size of the universe and whatnot, I also mean it figuratively.
If teenage hacker gets caught breaking into the high school system to change their grades then teenage hacker cannot break into the ultra top secret government systems. Sorry, but no. If they're not good enough to break into their high school without getting caught they're never getting into the NSA servers. Not gonna happen. Because there's a difference between small town high school computer security and top secret government computer security. If the first is too big a challenge for teenage hacker then, barring an alien brain upgrade, the second is way out of their league. You might as well have someone who can't climb a wheelchair ramp summit Everest.
Similarly someone who thinks "moment of inertia" is some esoteric bit of high level knowledge that ordinary people cannot grasp is probably way too low on the knowledge scale to be your scientist savior.
But also there is a literal sense of scale. If your movie is Cyber-Dinocroc vs. Zombie Sharktopus you might not think that real world concerns matter all that much, but you'd be wrong. Because if Cyber-Dinocroc goes tiptoeing unnoticed around small town USA mysteriously stealing microwaves and no one hears a thing, that's a serious problem if Cyber-Dinocroc is a 15 foot tall mass of muscle, bone, and metal. It doesn't matter if he's got a cloaking device, someone is going to hear him and he's going to leave footprints. At that point it doesn't matter if you've got the biggest effects budget known to humanity, top notch actors and Steven Spielberg as your producer, you fail.
Suspending disbelief on the big things is only possible when smaller things are kept in check. Giant monsters with enough mass to shake the earth do not get to sneak. It does not work that way.
Some of your characters being stupid is probably ok, all of your characters being stupid is a problem. The plot depending on all of your characters being stupid is a no-no.
There are too many examples to give an exhaustive list, so I'll just give one. Say that a dam is about to collapse and some people are watching it from a helicopter. Say the people decided to get a closer look coming in not just closer to the dam, but also lower than it. Say that the damn dam starts to come apart and the people in the helicopter are ordered to get out of there. Say that rather than using the helicopter's abilities to climb to safety or back away the people in the helicopter instead stay steadfastly in the only, very limited area, where the damn dam collapsing could hurt them and thus they die. Congratulations, you, the writer, have just failed at life.
Unless that was meant to be a clue that the machines are suicidally rebelling against us, or that somehow people have been made suicidal, or that aliens have started taking over the bodies of key people (like say helicopter pilots) in order to kill off important humans, or that the assault on Hell begins now so everyone go kill themselves (because a death short of mortal sin won't ensure that these people all wind up in Hell)... unless one of these things, you, the writer, have just failed at life. The best you can hope for is redemption, though you may have to work the rest of your days to reach that goal. You will never pull better than neutral. You had your shot, you blew it.
If your movie can be summed up as a two hour ode to suicide bombing that required giant sand worms (stolen from Dune because the effects department was too lazy to make new giant sand worms) to make suicide bombing seem like an even semi-viable option... no. Just no.
Do not pass go, do not collect 200 dollars. Just no.
Research is in no way necessary, this is a bad movie after all, but it couldn't hurt and it could prevent you from making stupid mistakes. Like, for example, basing a large portion of your plot on the false notion that NASA isn't a civilian agency or that supercolliders are power generators.
Not mean, but be. You might think that your movie is a wonderful metaphor for the difficulty of balancing work and family, but if you want your work to... work then you're going to have to take it on its own terms, not the metaphorical terms. That means that if someone is saying, "If you really loved me you'd take this time off and thereby destroy the world," you don't get to fall back on, "Well it's a metaphor for ordinary work so the person saying that isn't really a nihilist," because in the work itself your character just said, "If you love me you will destroy the world," which is not an appropriate thing for anyone save an evil overlord in training from another planet to say.
Generally speaking taking your work on its own terms rather than the terms you try to impose on it will make it a better work, even if it's about a giant earthquake that's impossibly large, a comet tiling the earth's axis to cause the world's magnetic field to collapse, or a swarm of giant piranha beetles.
Read some things about feminism. Seriously. Just do it. I'll be here when you get back.
It will probably be expected of you to have a romance plot or two in the movie along side the disaster/giant creature/giant creature disaster. Given what else you're going to have to fit into your movie, and the time you have available (two hours, less commercials) you're not going to have time to do these in any sort of depth.
Thus they will be superficial and your primary objective is probably going to be making it so they seem less superficial than they actually are.
You don't want it to seem like, "I just threw in a romance because it was expected," even if it's true. Especially if it's true.
General advice is to make sure that you establish that the characters have similar interests and common ground and whatnot, make sure that they actually are written as liking each other because while "Slap-slap-kiss," may be done left and right it is not in itself a sufficient to stand in for actual romance.
One shortcut often taken is to have the people not fall in love but fall back in love, this can work or it can fall flat on its face. Part of it will be what I said about the partners liking each other, but part of it will also be about why they broke up. If they broke up for a good reason, and that reason remains, then them getting back together won't feel real. If they broke up for a bad reason, then that can be worse still.***
What was the bad reason? Was it the fault of one party, both, or some external force? If Iago did it then Iago can be exposed and the two can get back together... maybe. Iago, after all, was only able to do what he did because of some deep character flaws in Othello which means that maybe Desdemona would be better off with someone else. On the other hand Desdemona loved Othello so who are we to argue with her choice if the relationship can be mended?
Especially because the idea of love as a reward is so ingrained in stories like this (the hero gets the girl/guy) the audience will be focused to a certain extent on deservingness, whatever that idea means to them. If they feel like one party doesn't deserve the other that stands a huge chance of things falling flat. As a general rule, if you're going to have a romance where one party doesn't deserve the other it's going to be more likely to work out if the work itself is focused on the undeserving party (Sabrina is told from the point of view of Harrison Ford's undeserving asshole millionaire who grows a heart, not the title character who is the chauffeur's daughter and deserves better than Harrison Ford's character.)
One last word of whatever. "My lover just died, now there's nothing standing in the way of us getting back together," is probably not a good sentiment to have unless the lover was a vampire who had the person under hypnosis that died with them. And in that case the sentiment should be more of, "Now that the hypnosis is gone I'm finally free to tell you how I feel: I love you." The monster/disaster conveniently doing away with someone's romantic rivals resulting in them getting their lover of choice just makes it seem like the person whose lover(s) died is a shallow person who will latch onto the nearest individual of appropriate gender.
When it comes to the part of the movie that places it on the Sci-Fi Channel: if you've got a disaster then all that you need to do is have the disaster follow consistent rules; if you've got a monster, more or less the same.
The problems will generally come up with people fleeing these things. The general rule is, "How would you run away?" That'll probably work out fine. The trouble is that, instead of doing that, people tend to try for more cinematic means of fleeing which are, unfortunately, less good.
One example that comes to mind is the person who stays behind to nobly sacrifice themselves to buy other people time. That's all well and good. The problem is that it almost never happens that way. See, that depends on the other people actually fleeing. Generally speaking, they don't.
Person stays behind to nobly sacrifice themselves to buy other people time and the other people stay behind to watch thus making sure that the person's sacrifice buys zero time and is completely meaningless. Or it gets worse.
Earlier today I saw a case where someone was trying to buy time but leaving open the possibility that he might yet live except... the people he was trying to buy time for refused to move and instead remained exactly where they were: on the only stairway out. Which meant that when he reached the point of, "That's as much time as I can buy, I should run now," the people who should have been long since gone were blocking his exit. If they'd left when he told them all three would have lived, but because they chose to stay and watch he was held up in his escape and thus died.†
Another example is, "I have this really good idea. Oh, it didn't work instantaneously on the first try. Let's abandon that and never mention it again."
Generally speaking any time that the characters are acting so stupidly that the audience wants to reach through the television and throttle them, that's not good.
A lot of such movies depend on this or that element of science to be wrong and thus depend on someone to point out, "Science says X which would mean that Y is impossible," and then be wrong. When making your bad movie you would do better to have this person be convinced by the introduction of new evidence and thenceforth prove useful than to have this person be an asshole.
Actually, you can have (this may surprise you if you're a standard See-Fee writer, but probably not if you're a standard reader of this blog) multiple scientists who initially object to [outlandish theory] on the grounds that it is outlandish, of whom most of which are willing to change given adequate evidence while one or two are unwilling to admit that they were wrong in standard asshole fashion.
* As can be determined by the pronunciation of proper nouns ending in "y"†† and the parallel structure implied by the double capitals.
** So, for example, if you're writing a town based creature movie it's important to know that the audience comes in with a set of expectations:
Whoever is in authority, be the authority political or economic, be it official or unofficial, will overlook the problem, initially as a result of understandable disbelief but, as time goes on, increasingly as a result of willful ignorance that is forced to become more and more willful as the movie nears its climax and evidence finally mounts. Instead he (or she, but usually he) will be more concerned with some social or economic event believing that that, more than the lives of the town's citizens, is key to the town's future.
The main character will not be an expert, instead the main character will call in experts. Two of them. One will be more hands on, the other more academic. They will not both survive. Which one dies is up in the air (in Jaws the hands on expert dies, in Arachnophobia the academic does.)
Whatever it is that the person in authority was concerned with, be it the beach season or the spring music festival, will be screwed over by the creature.
On the other hand, if your movie concerns an isolated group there are entirely different rules, in some ways fewer, in other ways more strict. The most obvious is the end. In the end there will be three or four survivors. The three will be the main character (who has thus far always been straight, this could use some subverting) the main character's romantic interest, and another guy. If there is a child the child will live. If the child is male he can be the other guy, but it is also possible for the child to be a fourth survivor in addition to those already listed. In the absence of a child there will not be a fourth survivor.
One of the things always survives. Generally as the last scene.
Before that there's generally someone who has some experience or at the very least requisite knowledge to become a fast expert, and it's always the case that what is being encountered is unlike anything before. Witness the queen of Aliens, or the fact that it's not just a shark it's a mega-, dino-, swamp-, sand-, super-, whatever-shark. There's always something new because no one wants to tread the same territory twice, or something. (This is true even if, as in Alligator II: The Mutation, they reuse footage from the original movie for the new creature.)
And so on.
*** I still remember, with a bad taste in my mouth, a movie where on learning she was pregnant a woman broke up with her boyfriend for no stated reason because he was a cop and thus might die on the job and, in her opinion, that's no way to raise a child so therefore she left him without explanation and he didn't even find out he had a child until said child was in her teens. The breakup was for a bad reason because it was a decision to unilaterally change the lives of two other people without so much as consulting either of them.
So ex's current lover, who gets along just fine with the daughter, hears this story and what she takes away from it is apparently that she should unilaterally change the lives of three people without consulting any of them. She dumps the ex so mother and father can get back together and raise now teenage daughter as a family because what the fuck?
Making life altering decisions for other people without consulting them was the problem, it shouldn't also be presented as the solution. Especially since other than her decision to dump the father so the original family can get back together whether they want to or not, it was otherwise shown that she'd make a fine stepmother and things would have been just fine that way.
† On the one hand, it was pretty clearly a writer subverting the three people live rule. He was, by all indications, supposed to be the "other guy" who lived. Thus it was mildly original and unexpected. On the other hand it was one of the most pointless deaths in movie history:
Doomed Guy: I'll buy you time.
Other two: No. We're good here.
Doomed Guy: You do realize that for me to escape I need to move through the exact spot you're in.
Other two: Yup.
Doomed Guy: So now would actually be a very good time for you to move.
Other two: Still fine here.
Doomed Guy: I've done all that I can, it's time for me to run.
Other two: Still fine here.
Doomed Guy: Seriously there's a giant prehistoric monitor lizard that's immune to cold who I just pissed off by poking his eyes out with spear on the advice of the now dead Saul Tigh from the new Battlestar Galactica so I'd like to run away now, could you get out of my way? Please?
Other two: I suppose we could start moving
Doomed Guy: Thank yo- ahhhrrrggghhhh!
Other two: Crap he's dead. Why is he dead? Let's angst about him being dead while we finally use these stairs to escape.
Xandy (Yes, it is a real name. It comes from Alexander the same way Sandy does, which is interesting because I would have guessed that Sandy came from Cassandra.)