Like several million people worldwide, I saw Spider-Man 3 this past weekend. And like a substantial percentage of these viewers, I got frustrated by the number of unlikely coincidences in the movie.

There’s nothing wrong with coincidence, per se. Almost every movie is going to have some incidents where one character just happens to be in the right place at the right time. In fact, many movies are built around a “premise coincidence.” In Die Hard, John McClane just happens to be in the building when the villains attack. That’s okay. McClane’s being there is part of the premise. Likewise, in the original Spider-Man, Peter Parker just happens to get bitten by the radioactive spider. No problem: it wouldn’t be Spider-Man otherwise.

The premise coincidence is one flavor of what I’ll call a Fundamental Coincidence: an accidental confluence of time, place and motivation which greatly impacts the story.

In a romantic comedy, when The Guy would have proposed to The Girl except that he just happened to overhear a conversation he interpreted the wrong way, that’s a Fundamental Coincidence. In the first Spider-Man, Norman Osborn just happens to be transformed into The Goblin just as Peter is becoming Spider-Man. That’s a Fundamental Coincidence, but we accept it because it feels true to the genre.

WARNING: MINOR SPOILERS FOLLOW. (Mostly things you’d glean the trailers or ads, but still.)

Let’s look at the Fundamental Coincidences in Spider-Man 3:

• The asteroid carrying the symbiote (utlimately, Venom) happens to land near Peter Parker. Peter doesn’t hear it, doesn’t investigate.
• The symbiote happens to attach itself to Peter’s scooter.
• Flint Marko happens to fall into the sand pit at exactly the moment the scientists test their billion-dollar Dyson vacuum.¹
• Flint Marko happens to have been the man who killed Uncle Ben. (A retcon.)
• Eddie Brock happens to be the only person in the church at the moment Peter tries to get rid of the black suit.

Any one (or two) of these Fundamental Coincidences would probably go unnoticed, particularly in a superhero movie, where credibility takes a back seat to spectacle. But put together, they make the plot feel rickety, particularly when you factor in the large number of what I’ll call Minor Coincidences — things that don’t fundamentally change the story, but feel convenient all the same.

1. The police chief decides to tell Peter about Marko now, even though he’s known the details for some time, apparently.
2. Sandman’s first attack just happens to coincide with Spider-Man getting the key to the city.
3. Eddie Brock is newly arrived at the Daily Bugle, and wants Peter’s job.
4. Gwen Stacy happens to be Peter’s lab partner.
5. Gwen Stacy happens to be in the skyscraper during the crane accident.
6. And she’s the police chief’s daughter.
7. And she’s Eddie Brock’s love interest.²
8. And Gwen happens to be at the fancy restaurant on the night Peter wants to propose.

Again, you could have several of these coincidences in any movie and no one would mind. It’s largely expected that familiar faces will become imperiled in a summer action movie, so #5 feels right. Likewise, the eventual discovery of Venom’s weakness is accidental, but that plays into the genre. No foul there.

My point is not to rip on Spider-Man 3, but to urge readers to look at their own scripts with an eye towards coincidence. If you’ve written a treatment, search for the following phrases: “at the same time,” “accidentally,” “luckily,” “unfortunately,” and “meanwhile.” They’re often a tip-off that you have events happening by coincidence. There’s almost always a better alternative.

Causality trumps everything

Given a choice, try to find cause and effect. One event happens because of something else we’ve seen — ideally, something the hero himself has done.

Instead of having the hero accidentally overhear a key conversation, get him actively trying to listen. Or have an interested third party steer him in that direction — perhaps for his own reasons. At every juncture where a reader could ask “Why did that happen?”, try to have an answer that isn’t, “just because.”

Although there are some convenient twists in the Harry Osborn plot (amnesia, for starters), the causality is clear: the New Goblin wants revenge on Spider-Man for killing his daddy in the first movie.³ It doesn’t feel like coincidence that Harry is flying around on his hoverboard. With two other villains desperate for scenes, the timing might not be opportune, but it’s clear why it’s happening.

Look for correlation

Rather than ask an audience to swallow a bunch of little implausibilities, try bundling them together.

In Heroes, imagine if each character had a completely unique origin story: Claire got her powers from a shaman; Sylar is an alien; Peter has a magic ring. You’d get frustrated pretty quickly, because a lot of screen time would go towards explaining why and how. Instead, the creators wisely decided the characters all had some mysterious gene mutation activated by an environmental change. The audience is willing to make that one big leap,⁴ because they’re not asked to make similar leaps each time a new character is introduced.⁵

For Spider-Man 3, I don’t have any magic answers on how to correlate these disparate threads — other than trimming one out, which wouldn’t be a bad place to start. But had the script dropped on my desk a month before shooting, here are a few thoughts I would have put out there in terms of the many coincidences:

• Both Venom and Sandman are forms of disembodied consciousness that control their host subjects — people and sand, respectively. That seems thematically promising.
• One asteroid feels random, while a meteor shower feels like an event that needs a superhero.
• Could this meteor shower overlap with Marko’s transformation or escape? Even if it’s just in the background, it makes them feel more united.
• Could Spider-Man be pursuing Marko at the start?
• Could we see the symbiote choosing Peter, because he’s the strongest creature around?

Chop it out

Often, the best answer when faced with a nagging coincidence is just to remove it.

• Do we really need the Uncle Ben retcon? It doesn’t have a lot to do with Marko’s sick-daughter motivation.
• Couldn’t Eddie Brock already be a stringer for the Daily Bugle? If he and Peter already have history, great.
• Does Gwen Stacy need to be Peter’s lab partner?
• Do we even need the police chief?

Again, my point isn’t to rag on Spidey, but to urge reader-writers take a hard look at the role of coincidence in their own scripts.

Some coincidence feels genuine. In real life, we do accidentally bump into old friends at the mall. And surprise in general is a good thing — catching your reader off-balance is a worthy goal. But if a significant portion of your plot depends on chance, that’s a good indicator something’s not fully baked. The best time to tackle these problems is in the outline, asking yourself not only what happens next, but why.

1. It’s never clear what they’re supposedly doing, or why they wouldn’t have, say, a lid on the pit. Or a videocamera to monitor the experiment. ↩
2. Revealing both of these points of information in one piece of dialogue was a particularly bold choice. ↩
3. I kept waiting for Peter to point out that Harry’s dad was a psychopath, but oh well. ↩
4. And a familiar leap, frankly, because of X-Men. ↩
5. Note that both the D.C. and Marvel universes do have multiple, often conflicting means of empowering their heroes and villains. This is good and fascinating, but I suspect it’s one reason it can be harder for a casual reader to pick up these titles. The time investment needed to get up to speed is significant. Quick: Is Scarlet Witch a witch? Ummm…Sort of. ↩