THE CLOCK is ticking and there is just one hour to locate and defuse the bomb in this locked, it's not a nightmare but one of the UK's fastest-growing game crazes now sweeping Scotland.

Escape rooms – in which teams of players have to solve Crystal Maze-type puzzles against the clock – first opened in Scotland three years ago and there are now 75 across the country. With new ones popping up every month in locations as unlikely as Orkney and Unst, the UK's most northerly inhabited island, experts claim they are becoming an increasingly mainstream part of our entertainment industry.

Themes for rooms – including secret bunkers, zombie apocalypse rooms, heist situations, as well as film and literature tie-in from Indiana Jones-style tombs to Harry Potter-influenced magical turrets – are attracting thousands of Scots each week with continued growth predicted, according to industry figures .

Escape room enthusiast and game reviewer Ken Ferguson, who runs blog site Exit Games, claims new rooms are opening at a rate of around one a day in the UK and with about 800 now operating he predicts that the market – which he estimates to be worth £40 million – will continue to expand throughout 2018.

He claims many have been inspired by TV shows such as the Adventure Game – screened by BBC in the 1980s and the Crystal Maze, first broadcast by Channel 4 in the 1990s before returning to screens in June this year – while the rise of TripAdvisor and other review sites have made it easier for people to track down far-flung rooms.

"More than anything, I think that people have moved from wanting physical goods to wanting experiences," he added. "Memories matter more than material objects. People are also looking for more interesting ways to socialise. It's not enough just to head to the pub for a drink, they want something more exciting.

"At some level it's – no pun intended – a form of escapism. People want to leave behind the stress of their lives and experience an adventure whether that's finding an ancient artefact, protecting the world from an impending disaster or escaping from prison."

Daniel Hill, managing director of the Escape brand, which opened Scotland's first room in Edinburgh in May 2014, said the growth of both his own business, and the industry as a whole, over the last few years had been striking. "When you look at the map [of escape rooms] you can see them popping up all over the world like the plague," he said.

Locked, at Summerhall on Edinburgh's south side, has attracted five-star reviews since its opening two years ago. Co-owner Jackie Jack believes people are attracted by the authentic feel of their rooms at the former small animal hospital – which lay derelict for 10 years – where themes have included a dissection room, an anatomy theatre and a secret lab. A second room is based around a break-in at a gin distillery. Pickerings Gin is based elsewhere in the building and owner Marcus Pickering is a fan.

Husband and wife team John and Sharon Rankin opened one of the UK's most northerly rooms in Lerwick, Shetlands, 18 months ago. Postman-cum-fireman John Rankin develops the games, changing them regularly in recognition of the islands' small 20,000 population and combining technology with old fashioned puzzles to create experiences to engage all ages. He has also developed games for other owners including a bomb-on-the-bus themed one in Missouri.

Linda Torrance of Escape Rooms Scotland, has rooms in Glasgow, Edinburgh, Dundee and Stirling.

"It's great fun but we also find that people learn something about themselves and how they react under pressure," she said. "We have families who go with their kids and when they come out they say: 'I didn't realise my kids were so clever'. It changes the dynamic between them. There are mental puzzles, maths riddles, association games. Once people try it they get the bug."