Children dressed as characters from Minecraft at a games convention.
Photograph: Andrew Chin/Getty Images
My son was seven when a paediatrician diagnosed him on the autism scale - but really, we had known for years. There was his limited vocabulary - a handful of words by the time he was three, and a habit of mixing up letters or relying on stock sentences. He found it hard to get on with other children at his nursery, and later, when he went to a much bigger school, it was obvious the experience was terrifyingly loud, hectic and incomprehensible to him. Meanwhile, if there was something he was interested in, whether it was Peppa Pig or Superman, he would fixate on it to the detriment of absolutely anything else. We knew where all the signs were pointing.
When you get this diagnosis, there are a lot of things you worry about: what will happen to their education; will they make friends; how independent will they be when they grow up? But a key element beneath all that is a basic human need: self-expression. Often Zac would try to tell us about things he liked, or stuff he had done at school, but his vocabulary would let him down, and he would get impatient. We tried to help, guessing what he wanted to tell us, but this frustrated him even more. It was heartbreaking. But, one day, when he was three or four, I was playing video games and I loaded up a PlayStation title called LittleBigPlanet; it's a kind of platform leaping game, like Super Mario Bros, and the hero is this cute little doll called Sackboy. PlayStation 3 has motion detectors in its controller, so when you tilt it in your hands, Sackboy nods his head in time. I let Zac play and he was amazed and delighted; when Sackboy responded to his commands, he fell about laughing. It was an instant connection.
We played together. LittleBigPlanet has an editor that lets you create your own levels, but Zac would just have fun selecting objects then dropping them on to the screen. He learned all the correct buttons very quickly. He seemed to have an innate understanding of what the game required. We played a lot of games after that, especially ones such as Lego Batman and Lego Star Wars, which let us play together cooperatively, completing missions and exploring. At first, I would solve the puzzles while his character smashed things up, but slowly our roles reversed. These games provided us with an uncomplicated space to just be together, to have fun. We did other stuff together, of course - we read, we played in the park - but games were something that we genuinely collaborated on. His autism was not a barrier. It felt like it was liberating to him.
LittleBigPlanet: a doorway to learning about games
Two years later, the building game Minecraft, which was already a huge hit on PC, was released for consoles. In Minecraft, players are free to do what they want: the game provides a huge natural environment, where you can build houses and castles, plant seeds or dig mines and search for buried treasure. Zac was immediately engrossed. To him, this was a vast playground, just brimming with new experiences and experiments. But it was also safe and bright and, once again, he understood the rules. He played with me and his younger brother Albie, and although he has never been patient enough to construct really elaborate buildings, he understands the systems, the way that day and night bring different challenges, and how to combine different elements to create useful new tools and items.
While he finds it difficult to sit down with some felt-tip pens and a blank piece of paper, he can spend hours crafting objects and building strange huts and twisting castles in Minecraft. We would work on projects together, taking part as equals, building little farms, or exploring vast caverns. As we played, he learned all the names of different things you could build or mine, and he wanted to talk and talk about the game. He found it difficult to express himself in the real world, but in Minecraft, all the tools and systems made sense. It was joyous to watch it happening.
And that's what led to my novel, A Boy Made of Blocks, which is about how a dad and his autistic son learn to build a relationship through Minecraft. I wanted to write something positive about the role video games can play in modern families; how they provide a permissive space in which to chat, play and be creative.
Related: Minecraft's creator will always be a hero to me, he gave my autistic son a voice
One thing I have discovered is that Zac is far from alone - many autistic children love video games. It's not hard to see why: they provide a very rich, compelling audio/visual experience that demands and rewards your full attention. A video game is a discreet world with very clear rules and boundaries - everything has a logic that doesn't change; these are properties that a lot of children on the autism scale seem to crave and respond to. But within these logical and comprehensible environments the player is also free to explore and mess about - you have agency and power. These are things all children lack to a certain extent, but it seems children with ASD can feel even more helpless and buffeted by the world around them.
Since I have been writing about this, I have heard from hundreds of game developers and parents about their own experiences. There are now dozens of autism-friendly Minecraft servers, such as AutCraft and SafeCraft, where people on the spectrum can go online and play together, without being bullied or insulted. There is a growing range of games that provide organised creative environments, from the huge Roblox community, where people make and share their own simple games, to Nintendo's wonderful Super Mario Maker, which lets kids and adults create their own levels for Mario to play.
Minecraft: 'a vast playground, just brimming with new experiences and experiments'
Simulation titles, such as Kerbal Space Program (build your own space stations) and SimCity (build your own town), also provide truly sophisticated tools for children to learn about science, architecture and lots of other stuff. Best of all, parents can learn too, and sitting down as a family to craft a rocket booster or an industrial zone is just such a different experience, where it's often the kids who take charge and adopt a leadership role.
Of course, there are lots of issues with video games and autism; studies have shown that children on the autism scale are more drawn to screen-based media, especially games, and that excessive play can lead to an increase in oppositional behaviours. As with everything else in parenthood, it's about setting and managing limits, and being engaged in what your kids are doing.
One thing I know is that when I wrote about Minecraft and autism for the Guardian, I had so many comments and emails from parents of autistic children who raved about their own experiences - who watched in surprise as their kids built elaborate mansions and rollercoasters and fortresses. I think games provide a form of interaction and creative exploration that are, almost by accident, fine-tuned to how some people on the spectrum see the world. I've found out so much about my own son through playing Minecraft with him, and watching him play with his brother, and listening to them plan and chat.
My next step is to try to help him learn to code, maybe using the simple scripting language Scratch. The line between playing and making games is crumbling. All play is, in essence, creative, but I think Zac discovered, on that first interaction with LittleBigPlanet, that games were going to be his medium of choice.
I guess the theme of my novel is that, as parents, we need to meet our kids in the places they are comfortable and then we can really get to know each other - it's just that sometimes those places exist on a screen, and we have to let ourselves go a little to find them.
A Boy Made of Blocks is published on 1 September 2016. Pre-order for £10.39 at bookshop.theguardian.com