Knightmare?” they ask when I explain what my show is about. “What, that one with the kids in the dungeon? And it was all done with computers and there was that guy with the beard, Trenger or something…”

“Treguard” I offer.

“Yes! Treguard!” They yelp back, lost now to the memories, eyes glazing over, back once more in front of the TV on a Friday after school, a belly full of well-earned biscuits now churning with fear and excitement as a wide-eyed man in a medieval costume stares down the lens and growls “Enter, stranger!”

Download the new Independent Premium app Sharing the full story, not just the headlines

“God I loved that show,” they say.

This is the conversation I have had an on an almost daily basis since I first helped conceive Knightmare Live, a stage version of the glorious kid’s TV show of epic quests, puzzles and monsters that ran on ITV from 1986 to 1994.

As anyone of a certain age will know, the original Knightmare saw teams of four children at a time face a terrifying quest through a brilliantly realised, computer-generated fantasy world of knights and dragons: think Game of Thrones with less nudity.

Their mission was to wrestle a magical item from the evil clutches of the denizens below Knightmare Castle. Only one of the children, “the dungeoneer”, was actually on the quest: moving from room to room, level to level, wearing the “Helmet of Justice”, which was so oversized that it covered their whole head, leaving them blind to anything not directly below them. The dungeoneer’s hopes of survival rested on the three remaining members, squeaking instructions at them through breaking adolescent voices while watching the action from a castle antechamber.

The genius of the show was the fact that the dungeoneer was actually walking around an empty TV studio in Norwich. Real actors played the various characters they met along the way but the dungeon itself and its many grizzly obstacles were all conjured up using blue-screen technology borrowed from TV weather forecasts.

If the team beat every puzzle and evaded every danger they would win the quest. But most of the time they just got horribly killed. Deaths were brutal and frequent. You picked up the chalk rather than the key? Dead. Sidestepped left instead of right? Dead. And with each fatal error, Treguard (Hugo Myatt), the presenter and dungeon master, would twist a droll smile and coo “Oooh, nasty!” It seems strange now that we made a hero of a man whose only hobby was sending blind children to their deaths. Simpler times I suppose.

Of course, since the late Eighties, countless kids’ TV shows have come and gone, so why is it that Knightmare is still so fondly remembered? (Only a few weeks ago, the first official Knightmare convention was held in Norwich.) Well, for one, it was technically ground-breaking; graphics that can still impress today played out to people who had no access to any sort of home computer. It also proved supremely thrilling, tense and dangerous, and, as current TV and film successes demonstrate, a fantasy world of swords and sorcery will always have appeal.

But for me the heart of Knightmare’s brilliance lay in the fact that it never spoke down to the gallant children who made up the soon-to-die teams. This was a game show with no real prize up for grabs other than glory, and precious few got even close to that. Survival, I have since learned, often hinged on whether the creator and producer Tim Childs thought you were playing in the right spirit; unbeknown to viewers, he would offer reprieves from death on the sly, should he think you had been unfortunate, or misread a room, rather than plain witless.

Last year I was lucky enough to witness this first- hand, when the Knightmare Live cast were invited to watch the filming of a one-off online revival of the original show. I have no idea who the team of disinterested, teenage YouTube celebs were, but they wasted no time in guiding their dungeoneer off the edge of a cliff. We watched on a parade of monitors, while Tim paced the room with the controlled air of a man blooded to such horrors.

He graciously allowed them to restart the room; undeterred, they swiftly walked off the ledge again. Tim visibly tightened, thumb hovering like a Roman Emperor, but once more he showed mercy, took a deep breath and explained that they needed to jump. With heavy expectation they entered the room a third time, but their cautious leap fell well short. The screen went black. For a while, silence, deliberation, then, through the darkness Tim muttered a single, final word: “dead.”

And so the gauntlet of killing dungeoneers has now passed to our humble stage version. As far as I recall, Knightmare: Live came about late in 2012 when our own Treguard (Paul Flannery) grew a slightly feudal beard and was looking for an excuse to keep it. Alcohol was involved certainly. We tracked down an old email address for Tim Childs and sent a rough proposal of the show. The reply was four exquisite words: “Welcome to level one…”

Sixteen months later, with one successful Edinburgh Fringe run under our faux-medieval belts, a national tour under way and another Edinburgh on the horizon, we can look back fondly on one of the few times we didn’t blearily regret opening a bottle of rum.

As we stood backstage at our first preview, raw from two months of building giant spider puppets and training an army of goblins, the papier-mâché helmet I wear to play the show’s scheming arch-villain, Lord Fear, cutting hard into my temples, we were fearful what the reaction from the fans might be, and curious if anyone would even care. Luckily for us, Knightmare fans make for remarkable audience members.

At the sight of an adult dungeoneer walking through a door and asking “Where am I?” the crowd wildly cheers as one. When the inevitable reply “You’re in a room!” sounds, any sense of control is lost.

Queues snake around the post-show bar, the crowd ever so politely waiting to get a photo of themselves wearing the iconic Helmet of Justice, while behind them any failed dungeoneers are, as ritual demands, taken outside, stripped of their lands and titles and shipped to France.

It’s been almost 30 years since the portcullis first rose on the beautiful computer-generated dungeons of Knightmare Castle, but love for this ludicrous, magnificent TV show continues unabated. To borrow a timeless dungeoneer trick: Spellcasting A-W-E-S-O-M-E.

‘Knightmare: Live’ is at the Udderbelly Festival on London’s Southbank on the 6, 13 and 20 June and continues touring the UK throughout June. It arrives at the Edinburgh Festival Fringe 30 July and runs to 24 August