If everyone has a book in them, then November is the month that many of those books are conceived. NaNoWriMo, or National Novel Writing Month, comes of age this year with its 21st birthday, and the concept remains as simple as it was in 1999: over 30 days, write at least 50,000 words of your novel.

Almost 368,000 novels have been completed by participants. There are no prizes or league tables, just the satisfaction of taking part – and the potential creation of something publishable.

There remains some sniffiness over NaNoWriMo in some quarters, usually published novelists who like to point out that some people write all year round. Half the world wants to write, it seems, and that means they think they can. Yes, writing a novel is hard work. And for every author that gets published, hundreds – possibly thousands – fail. But does that mean that we shouldn’t write novels just for sheer enjoyment?

It’s the same reasoning I used to apply to Parkrun, dragging my unfortunate frame around a 5km course every Saturday morning. I was not running with ambitions to compete in the Olympics or finish a marathon, but does that mean I shouldn’t have done it? It got me in better shape. Each time I improved a little. And I actually liked it. This is how we should approach NaNoWriMo. Beyond the writing, it is a big, global, online support group where writers can cheer each other on via social media. At the end of it, there might be 50,000 words of fiction and a sense of achievement. And it might well lead to bigger things.

Crime novelist Elizabeth Haynes has participated in NaNoWriMo every year since 2005. The words she wrote during NaNoWriMo one year formed the bulk of her first novel, Into the Darkest Corner, published in 2011. Every November for the last 15 years, she has used NaNoWriMo to kickstart books, and every year she is fed up with people snarking about it.

“Every year without fail I see something, a tweet, a blog, an article in a national newspaper, the gist of which seems to be, ‘Oh no, not November again. All those people thinking they can write. All of those manuscripts flooding agents’ offices! Please just don’t!’” she says. “It isn’t a competition. The world needs more novels, more readers, more writers. You want to be heard? Ignore everyone else. Work hard.”

Haynes had no intention to publish her first NaNoWriMo effort: “It was purely for fun. Publishing had always felt like something that happened to others, not me. I had three goes at NaNoWriMo before I had something with a beginning, a middle and an end. That was the first time I had something I thought I could actually edit.”

Many writers have used the intense 30-day deadline to get them going with a new project. Erin Morgenstern, author of The Night Circus and The Starless Sea, hasn’t participated for years, “but when I did, I always liked it for quickly getting words down for rough drafts without overthinking everything. It’s what got me writing seriously in the first place, because I used to write a few pages and hate them so I’d stop. Having peer pressure and a deadline worked wonders.”

What everyone can agree on is that bashing out 50k words is just the start of the journey, not the end. Most publishable novels are double that, and need to be edited within an inch of their lives. “I do maintain that the word ‘draft’ should be somewhere in the name, but National Novel Draft Writing Month doesn’t have the same ring to it,” says Morgenstern.

Five tips for taking part in NaNoWriMo

1) To hit the target, you’ll need to write at least 1,667 words a day. Sometimes the writing will flow; other days it won’t. If you write over on the good days, allow yourself a day or two off during the month to recharge. If you fall behind, catch up the next day rather than letting the word deficit pile up to the end of the month.

2) Never mind the quality, feel the width. Get the story down – you can polish your prose later.

3) Decide: are you a linear writer or a modular writer? If you’re the first, keep writing the story as it happens until you either finish it or the month ends. If you’re modular, write scenes from different points in the novel. They can be stitched together later. Both approaches are perfectly valid.

4) Let your characters drive the story. You can outline your novel, but leave some leeway for your characters to do unexpected things and go along with them for the ride. Plot and structure can be finessed in the edits.

5) Some days you will feel like deleting the whole thing and giving up. Don’t. If you can push on through the bad days, welcome to the world of writing.