Christina Patterson is a journalist, broadcaster and consultant. A former columnist at the Independent, she now writes mostly for the Sunday Times and the Guardian about society, culture, politics and the arts. She has won widespread acclaim for her campaigning work on the NHS and is currently writing a book about resilience, The Art of Not Falling Apart, which will be published by Atlantic Books in 2018.

Cities have to manage the tension between allowing for fun and imposing it.

On a mild evening in October, I tried to chase a shadow. The shadow was of a person, but the person wasn’t there. The dark shape in the pool of light was the shadow of someone who had already been and gone. It was a trick, a trick of the light, an installation, a piece of art. It was, in fact, a kind of game.

The shadow, and the pool of light, was one of a series dotted round the City of London. All were part of Culture Mile, a project that aims to turn the north-west corner of the City into a cultural area fostering “creative exchange”. The shadows were Shadowing, a work created by digital artists Jonathan Chomko and Matthew Rosier, which first appeared in Bristol in 2014 after winning Watershed’s Playable City Award. The award, as you might guess, is for city-based projects that are all about play.

The idea of play in cities is hardly new, of course. Most of us work and most of us play and cities have generally been planned to allow us to do both. The Romans, for example, took the idea of play very seriously indeed. I was surprised to learn, at the Colosseum this summer, that there were more than 200 Roman public holidays a year. The big treat on a day off was to watch slaves and gladiators being slaughtered. Now we can watch these things, or their fictional equivalents, on our TVs or our smartphones. Our public spaces tend to be for ambling or chatting or eating or drinking. Sometimes you’ll see something – a concrete ping pong table, a giant chessboard, steps painted to look like piano keys – that will make you feel that someone else is telling you, perhaps rather sternly, to have fun. But mostly, we’re left to feel that what we do when we’re not working is entirely up to us.

If Watershed and some other cultural thinkers have their way, this might change. It was Clare Reddington, Watershed’s creative director, and her colleagues who came up with the term “playable city”. It is, she told me, “a specific term, for a specific thing” and she said she found it “amusing” that it seems to have taken off, both in academia and beyond. “In Bristol,” she explained, “there was a whole lot of practice and artist’s work around being playful in cities”, but it was a conference in Guimaraes in 2012, then the European Capital of Culture, that triggered the idea for the project that she and her colleagues were to launch. “There were a lot of older people,” she said, “who were totally terrified at the notion of a smart city and how cold and alienating it was, so we decided to reappropriate smart cities’ technology for play.”

The result has been an annual conference, a prize and a series of projects in cities around the world. As well as Shadowing, there has been Urbanimals, a pack of origami-like beasts triggered by people passing or stopping; Empath, an audio-augmented reality experience that gives you a taste of someone else’s life; BikeTAG Colour Keepers, a street game using bikes and light; Hello Lamp Post, which invites people to use their phones to strike up conversations with street furniture; and Stop, Smile, Stroll, an “intervention” that will turn a pedestrian crossing into a “30-second party”. Personally, I quite like my lamp posts silent, my bike untagged and parties to involve nice conversation and a bottle or two of chilled Chablis, but the playable city concept has now involved nine cities on five continents reaching more than 1.1m people. So an awful lot of people clearly like it a lot.

The philosopher Julian Baggini, who lives in Bristol, is a fan. “Play,” he wrote in a piece in The Guardian three years ago, “is about interrupting the utilitarian efficiency of the urban environment and getting people to think about what actually makes us human.” One of the things that makes me human is a strong dislike of gimmicks, but Baggini anticipated the response of grumps like me. “Many of these projects might sound like rather contrived and artificial ways of dealing with the problems of atomized urban living,” he wrote. That, he says, is because “cities are in a sense artificial” and it “requires self-conscious, artificial interventions to disrupt this.”

Well, perhaps. But isn’t the idea of imposed fun in cities a bit W1A, a bit David Brent? It reminded me, I told him, of a crashingly earnest Hayward Gallery Show some years ago called Laughing in a Foreign Language. If this was your average artist’s sense of humour, you couldn’t help thinking, it was a foreign language indeed. “It’s not an infallible idea,” said Baggini. “It’s got to be done with care. It’s picking the right places as well, so they don’t become irritants to people who don’t like it. Your point is quite fair – if you’re in a residential area where there’s something intrusive, it would be like not being able to escape the world’s worst party.”

Luckily, people have been able to escape, because the playable city projects have so far all been temporary. Not least because the funding – usually a mix of Arts Council, British Council, and local public and private sources – has been pretty modest. Were there, I asked, any projects he really didn’t like? There was a pause. “They had one where they had talking lamp posts,” he said. “It was a bit too cumbersome and a bit too tricksy, and it didn’t really work. It was a failed experiment. That’s fine. I’ve got nothing against failed experiments.”

Failed experiments are clearly less serious for artists than for brain surgeons or even architects. Much, much better to have a slightly irritating pedestrian crossing for a few weeks than a whopping great tower block wrecking a view or blocking out light. And in fact there have been some “playful” public arts projects in Bristol that have been a spectacular success. Bristol artist Luke Jerram’s Park and Slide, for example, has been copied in more than 60 cities around the world. Jerram crowdfunded the 300-foot water slide he installed for one day in one of Bristol’s main shopping streets and 96,000 people applied for a “ticket to slide”. Only 360 were lucky. More than 65,000 people turned up to watch. “It generated,” he says, “huge amounts of publicity. Something like 500 press articles around the globe, reaching around a billion people.”

But the project he’s proudest of, he told me, is his pianos artwork, Play Me, I’m Yours. The idea is simple: stick a few pianos in a few public spaces and see if people play them. And they do. Jerram has now installed 1,700 pianos in around 60 cities worldwide. “The project has led to several marriages,” he told me. “It has led to some people being discovered as musicians and being given recording contracts. It even helped change the UK licensing laws. It has been copied so much, you see pianos in airports and train stations around the world. I saw one on the border between North and South Korea!”

“I’ve been doing this for 20 years now,” he said, “so I’ve learnt how to engage and interact with the public, what they’re willing and not willing to do. It’s quite complicated. It’s the rules of engagement, really. The rules of engagement of the Science Museum or an art gallery are completely different to those in a bus shelter. There are different languages.”

There are indeed. It is, to be honest, hard to imagine all that many old people tapping a smartphone to chat to a lamp post or dancing as they cross a street. But Clare Reddington is adamant that their technological “interventions” are not aimed at the young and digitally savvy. “We have a rule for ourselves that our work has to be in non city-centre spaces,” she said, “and that the technological barriers have to be incredibly low to enable people to participate, so we are overtly not trying to work with hipsters… We’re starting a conversation about the changes citizens want.”

What isn’t yet clear is where that conversation is leading. Reddington has commissioned research from the University of the West of England to “benchmark which playable city interventions are welcomed and the changes they make, or the conversations they start”, but it’s still in the early stages. The big question, I suppose, is what you do with those conversations. If people say they’re lonely, miserable, or unable to afford a decent home, is a speaking lamp post really going to cheer them up?

I don’t know about a speaking lamp post, but I can think of plenty of other things that might. The water jets at Somerset House, Granary Square, the South Bank and the Olympic Park give joy to children and adults alike. The London Eye, which was only meant to be up for a few years, has given rides to more than 60m people and become part of the London skyline. When it opened in 2000, it was the world’s tallest Ferris wheel. The whole South Bank, in fact, now feels like a cross between a giant playground and a funfair. For me, it’s hit and miss. The bars, cafes, deck chairs, and roof garden on the Queen Elizabeth Hall and the public art installations are, for me, mostly a hit. The giant purple “udderbelly” tent that sometimes springs up near the Eye is a miss. It is, of course, all a question of taste.

And that’s the challenge. We all have our own taste. We all have our own ideas of play. We might even have our own ideas about what exactly play is for. Is it to cheer us up? Is it to make us more creative? Is it to make us less fat and more fit?

If so, it’s worth noting that recent research from the universities of Oxford and Hong Kong has shown that people who live in cities are healthier and happier than people who live in the countryside. The research suggests that people who live in areas where there are more than 32 homes per hectare are the healthiest. Perhaps it’s because we have parks. It was the Victorians who introduced public parks to cities, 177 years ago. In a park, you can walk. You can run. You can kick a ball. You can have a picnic. You can read in the sunshine. You can feed the ducks. You can dream.

What we all need, surely, is to dream. For that, it helps to have something of a blank canvas. An open space. A stretch of grass. A pretty square, or courtyard, perhaps some sunlight bouncing on a fountain. We need people to design cities in ways that will give us these spaces. Sure, give us a piano. Sure, let’s have the occasional ride on a slide. But let’s keep it simple. I do not want to spend any more time fiddling around on my phone.

When I went to see Shadowing, I struggled with the interactive map. It took me ages to find the lamp posts. It took me ages to see the shadows. At each of the three lamp posts I found, not a single other person noticed the shadows or stopped. That’s fine. It’s a subtle work. And people were busy trying to get to the places they love, where they could do what they want.