TV’s Stranger Things and Game of Thrones have brought millions of new players to the classic fantasy game

For the past few days the ancient walls of Northumberland’s Langley Castle have resounded to the clang of clashing broadswords and the battle cries of angry goblins.

A band of mercenaries emancipated a caravan of slaves, a princess captured a corrupt warlock, and then there was that unfortunate business with the insane dark elf sorcerer.

The entire castle was taken over by a party of 42 gamers – mostly American – who had each paid a king’s ransom of $4,000 (£3,200) to play Dungeons & Dragons for four days in a genuine medieval stronghold turned luxury hotel.

Once thought uncool, and derided as strictly for the nerds, D&D – as gamers call it – is back, and it’s big business. Helped by its depiction in TV shows such as Stranger Things and The Big Bang Theory, and the spike of interest in the fantasy genre created by Game of Thrones, sales of D&D material have grown in double digit percentages in each of the past five years. With more than 40 million players, the game is now more popular than it has ever been since its invention in 1974.

Actors such as Drew Barrymore and Matthew Lillard are fans. The author and intellectual Ta-Nehisi Coates has talked of his love for it. Fashionable bars and cafes throughout Britain are hosting D&D evenings, and Games Workshop, the high street store selling materials for role-playing games (RPGs), posted record profits last year, helping it towards a market value of more than £1.5bn.

Entrepreneur Ian Livingstone co-founded Games Workshop in 1975 and was responsible for first bringing D&D, created by an American game designer and now published by Hasbro-owned Wizards of the Coast, to the UK more than 40 years ago. He is still involved in the games industry.

“I think one of the most important factors in D&D’s current success is an American web series called Critical Role, which has its own channel on Twitch [a live streaming platform for gamers], and is also on YouTube,” he says. “It’s a bunch of really cool professional voice actors who play D&D and stream their session so it’s become a kind of spectator sport. They’ve had 68 million views. It’s like watching spontaneous, unscripted theatre, and it’s helped to bring D&D to new audiences.”

Facebook Twitter Pinterest D&D features in Netflix’s Stranger Things. Photograph: Courtesy Netflix/AP

Livingstone was also involved in the computer game industry, which was once expected to ring the death knell for “analogue” games such as D&D. So why didn’t video kill the RPG store?

“People don’t want to live their entire lives in a digital space – they want analogue entertainment as well,” Livingstone says. “We see the same thing with the resurgence in board games, in vinyl records, in physical books. I think people require a balance between digital and physical.”

James Newman is professor of media at Bath Spa University and a researcher in games and gaming cultures. Despite the role of online platforms such as Twitch, he says: “Part of the increased popularity of D&D might be a reaction to the virtuality and immateriality of digital games. D&D remains an inherently physical, material experience, with books, dice, character sheets and so on. It’s also very often a game played face-to-face, around tables.

“If we look at the game itself, we see it has changed quite a bit over the past few years. There has been an important shift in focus away from the intricacies of rules, game mechanics and statistics, and more towards creating narratives and rich storyworlds. As a result, the game is more accessible and more inclusive than ever before.”

In the latest season of Stranger Things, which has set new viewing records for Netflix, the heroes are turning their back on D&D now that they are teenagers, but in real life 60% of players are older than 25, according to Wizards of the Coast. Almost two-fifths of players are female, and that proportion is growing.

In the 1980s, D&D and other RPGs fell foul of the “satanic panic” over supposed ritual abuse and were thought by some to be a gateway to devil worship. Now it is believed that playing could have therapeutic benefits.

Aoife Wilson, head of video at gaming website Eurogamer, says: “I’ve spoken to people who have used their D&D characters as outlets to channel or work through their own grief and trauma, and spoken to Dungeon Masters [the person who runs and referees a game] who have written and built campaigns around real-world events, which has led to honest and invigorating discussions within their friendship groups.

“In the end, D&D is interactive storytelling that promotes friendly collaboration, creative thinking, active listening and keen problem-solving skills, all done in a safe, social and positive environment. Playing and developing your character can be a real confidence boost, too.”

The Langley event was organised by a Canadian company called D&D in a Castle, which is already taking bookings for next year’s trips. Among the players were a medical physicist, a lawyer and a financial investigator.

Margaret Livingstone-Evans, general executive manager of Langley Castle, says: “They are very nice, interesting, polite people. They’re talking about wanting the castle for a couple of months next time.”