Scaling London’s tallest climbing wall after a sherry-laced lunch isn’t easy, especially when sweating inside a Father Christmas suit and lugging a sack stuffed with copies of the Guinness World Records. There’s a reason, though, that David Broughton-Davies has worked as a professional Santa for over two decades. He is committed to the bit. And on this day in 2001, he had not merely climbed the Westway Sports Centre’s 44-foot wall, which had a chimney perched on top, he had also aced a mince pie eating competition, and delivered a resoundingly low ‘ho ho ho’, securing him the title of the Guinness World Records Ultimate Santa. For his efforts, he also received a trophy in the shape of two stout, golden boots.

Such fun and extreme jollity is an essential component of the festive entertainment universe, which is populated by thousands of genial Santas, impish elves and cosy, trad-wife Mrs Clauses. Every year, from November, they are suddenly everywhere: radiating cheer from twinkling grottos, dismal pub corners, shopping centre sleighs and corporate Christmas parties.

You probably haven’t given it much thought, but festive entertaining is actually a pretty unique job. On the one hand, it involves long shifts and inevitable interactions with screaming children and demanding parents. But, given Santa and his entourage are fairly synonymous with goodness, it also holds profound moral and ethical weight too – and is central to constructing and upholding the childhood-defining lie that is the Santa story. Broughton-Davies, who obviously loves his job as the Selfridges Santa and also has a side hustle delivering personalised Christmas messages on the app Cameo, adores igniting a sense of magic in children. ‘When people say that they’re in the church because they had a calling – that is the nearest thing I can equate to this,’ he says. ‘There’s something about doing this which not only makes them feel better – but it makes me feel better.’

A sociologist at the University of Essex, Philip Hancock, has studied Christmas extensively, interviewing countless professional Father Christmases in the process. His research raises some key points that are fundamental to understanding the mythos of the role. First, Hancock explains, Father Christmas is a simulacrum: an extensively copied icon with no clear original, who comes alive for two months of the year. Second, unlike most roles, where audiences tacitly understand you’re playing a part, children actually believe you are Santa. ‘You can’t just perform Santa,’ Hancock writes in one of his academic papers, arguing that the role requires an ontological shift. ‘You have to inhabit his identity physically, emotionally, intellectually, ethically.’

For those who take the role seriously, inhabiting Santa demands extensive preparation. While there are plenty of books and manuals on the topic, courses provide a more immersive experience. In the US, the International University of Santa Claus boasts some 5,700 graduates, while James Lovell, who started his London-based school in 1997, has trained more than 500 elves and Santas. Lovell’s lessons focus on mythology and heritage – the story of Sinterklaas traces back to a 4th-century Greek bishop called St Nicholas, who apparently bestowed many miracles, including throwing bags of gold down a chimney to stop his daughters being sold into slavery. Classes also cover the art of the all-important ho ho ho. ‘A mistake people make is they say the wordsho ho ho”, which is ridiculous,’ says Lovell. You must instead ‘reach down into your ample tummy’ and ‘suggest it with an actual laugh’.

Proper costume is essential, as sloppy choices have consequences. ‘If you give a child a duff Santa experience, you’ve ruined a very important part of their childhood,’ Lovell warns. Cheeks are pinched rosy; eyebrows whitened; red coats ideally made from quality felt. Leather belts should be cinched with a substantial buckle, glasses rest wisely on the tip of the nose, and there’s no replacement for a good boot. Boot covers? An absolute no-go. White gloves dodge over-inquisitive questions as to why Santa had tattoos on his hands last year. Under no circumstances should you wear an all-in-one beard and moustache. (Broughton-Davies’s bespoke beard was moulded to his jaw by the wig and beard-maker who worked on the Harry Potter films). Given how much of the face is obscured by hair, wise and twinkly eyes are crucial. ‘Look them straight in the eye. They have to know they are in safe Santa hands,’ says Broughton-Davies.

At Selfridges, where Broughton-Davies works, Father Christmas isn’t statically based in a grotto, but roams the various floors of the store, meeting children as he goes. ‘Some are catatonic,’ he says – after all, this is probably the first time they’ve met a celebrity. He’s heard Paul McCartney has a similar effect on people, and it frequently falls on him to break the ice. ‘It’s the same with Santa. Santa has to make that first chat.’ This is why ‘Santa Banter’, to use an industry term, is so important. Heartening warmth and jocularity are among other techniques that help persuade hundreds of children a day that you are indeed Santa – and therefore omniscient. Not only do you already know exactly who they are (Santa must never ask a child their name – he’s met them many Christmases in a row), but you will be delivering exactly what they want for Christmas because you’ve already received their faithfully posted Christmas list. A trained actor like Lovell and Broughton-Davies, Kevin Moxon now works at Butlins. But he was one of the Harrods Santas for years, welcoming everyone from oligarchs’ offspring to the Osbornes into his grotto which, for some years at least, was studded with Swarovski crystals. To make the whole experience as magical and believable as possible, Moxon hand-made huge leather tomes, faithfully scribing in their gilt-edged pages the names of children who visited him, and what they wanted. (The grotto is now closed, but one of these books sits in the Harrods archive). Positive questioning and avoidance also come in handy, especially when older children start to get suspicious.

‘Are you the real Santa?’