At Sports Interactive we’ve been making football management games for more than 20 years. We aim for Football Manager to be not only the best simulation of its type, but to create a world to escape into. People play the game for a long time – on average 240 hours a year. That takes them far into the future of their parallel universe. Brexit is going to affect football. So we had to have it in the game.

Before the referendum, I made sure my business had a plan for all the possible outcomes. And, unlike our politicians, I was happy to go public with it. As part of this I started talking about how it could affect football. There had been a claim during the campaign that 200 players at top flight clubs in the UK wouldn’t get work permits under the current football system if we left the EU. I worked it out to be closer to 150, but it included the likes of France’s N’Golo Kante and Dimitri Payet, both of whom were among most people’s players of the year last season. It also included most of my beloved Watford’s squad.

Facebook Twitter Pinterest Would France’s Dimitri Payet and N’Golo Kanté have to apply for work permits? Photograph: Franck Fife/AFP/Getty Images

When the referendum result came it was a shock – not because pollsters got it wrong. That’s not unusual. But this time the bookmakers got it wrong – and I’m yet to meet a poor bookie. What shocked me even more was the “What do we do now?” coming from the government. The Brexiters didn’t have a plan – it wasn’t their job apparently. Yet I’d spent the months leading up to the vote researching what could happen either way.

Making games is fun. But it’s also a business that requires highly skilled people who are not paid as much as they would be for similar roles that are less fun. The shortage of computer programmers in the UK, in particular, is due to a lack of investment in education. Thankfully, because of the work of Ukie (the games industry trade body) and industry veteran Ian Livingstone, programming was added to the national curriculum in 2014. Which means in 10 years’ time, we might not have a shortage any more. But 10 years is a long time. So games developers scour the world for talent. Roughly one-third of our most skilled team members are from inside the EU and outside the UK.

There have been indications from Iain Duncan Smith that software engineers will have a “softer” route to getting work permits than some others. If true, then that will make things easier on the senior level, but likely not on a junior level. And in all probability our employees will be able to stay in the UK after the negotiations. But early indications are that some won’t want to, and some may not be able to. Many are in relationships – and just because their jobs are safe it doesn’t mean their partners’ jobs are. And, in any case, some don’t feel welcome in this country any more – the worst outcome I’ve seen first-hand of the referendum.

Martin Rowson on the government's Brexit plans – cartoon Read more

But we had planned for all this. That meant that after the result attention turned to the one thing I hadn’t prepared for – how are we going to represent Brexit in our game? We couldn’t simply ignore it.

None of us knows exactly what is going to happen. Football is a huge industry in the UK that generates enormous amounts of revenue for UK plc. If the current work permit system stays, but includes EU countries, it will affect the quality of players in the Premier League. And those who might normally come here will go elsewhere, making those leagues more attractive, particularly to the foreign broadcasters that provide hundreds of millions in revenue per year to the Premier League and beyond.

So I had to try to work out every possible Brexit scenario. How long would it take? What work permit system would be implemented? With the current rules meaning so many players wouldn’t be able to play here, could it still be kept in place? If so it would force clubs to play more homegrown players, which could be good for the international teams – as young players find their route to the first team has been cleared of talented foreign stars. But the current rules could also be relaxed.

We may negotiate freedom of movement for workers as part of the Brexit negotiations. Or government could decide a special exemption for footballers. And that could be the case even if it isn’t negotiated the other way – we could end up with as many EU players still being able to come here as possible, but UK players being classed as foreign elsewhere.

All of those possibilities have percentage chances of happening in the game, as does the time it takes for the negotiation to happen. It is even possible for Brexit to be repealed – although the chances are pretty slim.

Why had a game developer seemingly put more preparation into this most important of decisions than our government?

But other questions came up too. Both Scotland and Northern Ireland voted to remain in the EU. So even though the likelihood is very small, we had to add in the possibility of Scotland deciding to leave the UK, while trying to stay in the EU. Northern Ireland is more tricky – but, in theory, should no one come up with a decent plan that keeps both Irelands happy regarding the border there could be calls for independence there. I was recently called “foolish” by the DUP for even bringing up the possibility – although this is the least likely scenario in the game.

It was only a few weeks ago that we announced that Brexit would be a factor in the game. I woke that day to Marina Hyde retweeting the Telegraph news story: “When you just KNOW Football Manager has more of a Brexit clue than Liam Fox”. While flattered, surely she was wrong? Surely politicians had thought all of this through, but were just keeping their cards close to their chest? What we’d done was far from rocket science, but it was being treated as though it was.

Media requests flew in. I ended up on the Daily Politics, explaining what we’d done to a Tory and Labour MP. Other politicians got in touch. And then I was invited by Ukie to speak to a bunch of MPs behind closed doors. Why had a game developer seemingly put more preparation into this most important of decisions than our government?

In my own current “save”, Brexit kicked in at the end of season three. Unfortunately I got one of the hard options, where all non-homegrown players are now going through a work permit system, albeit one that’s slightly relaxed. It means I can no longer bring in that 19-year-old Italian keeper I’d been eyeing up as one for the future. Instead I have to wait for him to break into the Italian squad, and play 30% of their fixtures over the next two years. Then he’ll be mine. Meanwhile, my TV revenue has just dropped by a few million. Let’s hope that doesn’t continue, or I won’t even be able to afford him.