Every year on 28 April we celebrate Terry Pratchett Day, marking the birthday of Sir Terry Pratchett and the extraordinary worlds, characters and ideas he gifted to us. We hope you will join us in our mission to bring Terry’s books to readers everywhere – young and old, existing fans and new readers alike. Share your love for Terry by visiting your local bookshop or library where you will find activities and games to take part in, or post your memories of Terry or of your favourite book on one of the many STP social media pages or fan forums.

This year’s theme is: Terry Pratchett’s Hat Parade! But why? Well, on the Discworld, hats are not just hats. They are symbols, statements, warnings and occasionally snacks. Today is about celebrating that spirit with humour, imagination and a very light dusting of chaos.

On the Discworld, hats are never just hats. They are declarations. They are job descriptions. They are, in some cases, public warnings.

In Terry Pratchett’s worlds, what you put on your head matters almost as much as what’s inside it. A hat tells the world who you are, who you think you are, and – crucially – who everyone else believes you to be. And belief, as any Discworld reader knows, is a powerful force.

Take witches. A witch’s hat is tall, black, and unapologetic. It exists not to keep the rain off (though it can) but to make a point (if you’ll pardon the pun). Witches wear hats because people expect witches to wear hats, and because it’s useful to be recognised as someone who should not be trifled with. On the Discworld, the hat doesn’t just mark the role – it helps create it. Wear the hat long enough, and the hat wears you right back.

This idea – known to witches as “headology” and to everyone else as common sense – is central to Terry Pratchett’s comic genius. Hats are shorthand. They save time. Why explain that you’re a wizard when a pointy hat with “WIZZARD” embroidered on it will do the job immediately? (Spelling optional.)

But Pratchett’s hats are never only jokes. They’re tools for exploring identity, power, and performance. Characters on the Discworld often become what they are seen to be. A uniform, a badge, a crown – or yes, a hat – carries narrative weight. When people believe in the hat, they believe in the authority beneath it. And when belief falters, things get . . . interesting.

This is why hats matter to Sam Vimes, who knows that a badge can be more dangerous than a sword; to Moist von Lipwig, who understands the theatrical value of a good costume; and to Granny Weatherwax, who knows exactly when to put the hat on and when to take it off. The hat is never accidental. It’s chosen. Or at least, allowed.

Of course, Terry Pratchett being Terry Pratchett, hats are also funny. They get sat on. They get eaten. They get mistaken for other things entirely. They are worn by orangutans with impeccable dignity. They are blown away at inconvenient moments. The humour is physical, visual, joyous – but beneath it lies a very sharp observation about how humans organise the world.

So today, on Terry Pratchett Day, when we tip our hats to Sir Terry, we’re doing more than joining in the fun. We’re acknowledging a writer who understood that stories, like hats, shape the way we see ourselves – and that sometimes, the bravest thing you can do is put one on and step into the part.

After all, if you’re going to face the world, you might as well wear a damn good hat while you’re doing it.

Paul Kidby with STP’s portrait