Sometimes stories hinge on coincidences, and personally I think that’s fine. Sometimes. It depends on the size of the coincidences, the amount of them, and how they are used. I think you can get away with stretching plausibility a bit, but stretch it too far and readers just won’t buy it.
Now, some readers will likely be turned off by any coincidence being used to drive the plot along. But you can say that about a lot of things. You can’t please everyone; the aim is to try to keep a significant amount of readers happy. You want the majority of your readers not to get annoyed at you.
So, the size of the coincidences. I’ll give some examples of what I think is acceptable, and what might be pushing it a bit.
For one, let’s say you have two important characters just happening to bump into eachother at an opportune time. Why are these characters important? Do they have pre-existing links to one another, the villain, or any other important character, or does one or both of them only end up being important because of this meeting? If it’s the latter then it’s not even a coincidence, it’s just something that happens, if it’s the former, then it is. And I think that in many cases it could be an acceptable one. Could be. I’m going to be supremely unhelpful and point out that every story is different, and every writer has to make their own judgement call, taking the opinions of others they’ve let read the story into account.
I think where it would be pushing it a bit in this case would be if one of the characters wasn’t actually aware of their importance, but decided to tag along with the rest of the plot anyway. If they both have at least some knowledge of their links, and they happen to come across eachother, it can make sense for them to team up.
And the scale the story takes place on matters too. If all the action is confined to a smaller area, and everyone important is in that area, it’s more likely the important people will bump into eachother. If the story is on a worldwide scale, and the characters with a pre-existing link to the plot could be anywhere in the world, then it’s a bit less likely.
I feel I’m having trouble wording my points in a way that actually makes sense, which is a fine quality in an aspiring author. I apologise if I’m not putting them across very well.
I will move on to another sort of coincidence.
Let’s say your characters have a problem that needs to be overcome that requires a specific skill, or item, or bit of knowledge to do so. So one of your characters needs to have that. In the case of items or knowledge it’s better if they didn’t just happen across it; if they just happen to have picked up the right thing or overheard the right conversation. Now if it’s something they knew they might need, and they actively sought it out, that’s very different; once again, not a coincidence. But if they didn’t know, then you want to make it pretty plausible. You can write it so there’s a decent chance of them stumbling across what they needed, or you can make it so they’re always picking up stuff they think might come in useful, or have a habit of eavesdropping.
If it’s a skill that’s needed, and no-one knew it would be needed, then it depends on the size of your party of characters, and how common the skill is. What are the odds that one of them will have this specific ability if they haven’t deliberately sought someone with it? Some things are common enough that it’s fairly likely even one character on their own will be able to do it, but others are so rare that even if you get a relatively large party together, the odds are none of them are going to be able to do that one specific thing. But it is more likely in a bigger party.
So that’s some examples of what sort of size coincidence I think a writer can get away with, and what might be two far.
Onto the number of coincidences. My opinion on this one can be summed up more briefly. The more you rely on coincidences, the more you’ll stretch a reader’s patience. I think once you’ve had one big coincidence, or two or three small ones, that’s really it. A writer should be capable of writing their way through things without using a coincidence every time. Well, a good writer shouldn’t ever really need them, but they happen in real life, so they can happen in stories.
And it also matters how you use them, and where in the story they come. If you’ve set up a really big problem that your characters need to overcome then you can’t hinge the resolution to that on a coincidence. If you’ve written yourself into a corner and that’s the only way out, then it’s better to go back and rewrite it so it’s not the only way. It’s not very satisfying to see characters win by sheer chance. Maybe some small coincidence combined with other factors could work, but personally I’m not sure it should be risked. I’m generally OK with moving a story along, or even getting it started, with a coincidence, but I don’t feel it should be resolved with one.
I also feel I should say that there’s some cases where a coincidence may in fact trigger the denouement of the plot, in certain genres. I’m thinking of romances and slice-of-life genres. A character stumbling upon a bit of knowledge another character didn’t want them to have could be the big drama that has to be resolved. As long as it’s plausible that they came across this then that’s fine, and I think it usually is. It’s generally not too hard to concoct a reasonable secret revealing coincidence; all it takes it someone to wander in at the wrong moment or something.
And sometimes they might be used as misleader. In a mystery, you’ll often get loads of threads that don’t go anywhere because they’re trying to keep people guessing. ‘Oh, this guy’s secretly a big criminal – but he’s nothing to do with what’s happening, he just happens to be here’. ‘This woman absolutely despised the dead guy – but she just happened to be nearby when he was killed’. That kind of thing. This might get a bit much at times, but to me it’s just part of the genre. It keeps it interesting.
There’s probably other ways you can use coincidences that I’m not aware of or that just haven’t come to mind, but I think that’s basically everything I have to say on the matter, at least for now. As I noted, each story is unique, and ultimately it’s up to the writer to decide what is and isn’t too much. I hope I’ve managed to be at least understandable. Thanks for reading.