It's one of the biggest accolades that a sitcom can receive. No, not a British Comedy Award or the fan worship of Johnny Depp – but the request, made much earlier in the year (the choices are usually finalised by February), to produce a Christmas "special".
The bestowing of a festive-themed episode is traditionally a sign that the bigwigs in commissioning – predominantly at the BBC – consider a series to be sufficiently important to unite the nation at the one time of the year when families might just be watching the same television set. These anointed comedies are being asked to follow in the footsteps of such audience-pleasers as Morecambe and Wise, Del Boy and Rodney and the Vicar of Dibley. No pressure then.
But is this flattering request to produce a festive special an honour or a poisoned chalice? Is the responsibility of keeping the population amused at such a heightened time of the year more a burden than a gift? Can the writers ever satisfy the weight of expectation, or is the Christmas "special" forever destined to disappoint?
Take last year's The Royle Family (I wish you would, as the old joke goes). "The New Sofa" was as flat as a futon. Drifting aimlessly through the digital-sphere with nothing to view, I can usually alight on an old episode of Caroline Aherne and Craig Cash's sitcom like a shipwrecked mariner fastening to the side of a lifeboat. Half an hour of guaranteed amusement. But this one didn't work. Perhaps it was because they took it out of the Royles' living room – to Dave and Denise's – or perhaps it was the absence of Nana (killed off in the exemplary "The Queen of Sheba") and Ralf Little's Anthony, but it was a severe disappointment from the opening credits to the closing Oasis theme song.
In a normal week this might not have mattered, although it would still have been noteworthy given the usual surefootedness of this show. But as the climax of BBC1's Christmas-night viewing – the fairy atop their Christmas tree – it was like opening a present you confidently expect to be a box-set of Mad Men, only to discover that you've been given season 18 of Heartbeat instead.
As it happened, The Royle Family was the fourth-most-watched programme last Christmas (behind Wallace and Gromit, Doctor Who and EastEnders), with 10 million viewers – not a huge audience in historic terms (the 1993 Only Fools and Horses Christmas special attracted over 19 million), but still a lot of people to disappoint on the one night of the year when they don't want to be disappointed. Hell, isn't the rest of Christmas anti-climactic enough?
This year's Royle Family Christmas special, "The Golden Egg Cup", is already in difficulties, by all accounts, a faulty camera having necessitated a £100,000 re-shoot. Although Aherne and co-stars can probably relax because the weight of this year's seasonal expectations has passed to another BBC1 sitcom. The recipient of three prizes in last weekend's British Comedy Awards, Outnumbered, with its trio of hilariously improvising child actors, is the "special" carrying this year's burden of anticipated pleasure. Surely only disappointment can follow.
Not that Hamilton and Jenkin will have much time to worry about their creation's reception – because as you read this they are sweating over a hot editing suite. And that's another thing about Christmas specials. Although it would be wrong to call them an after-thought, they do seem to be left rather late. I remember last year interviewing Phil Mealey, Aherne and Cash's co-writer on The Royle Family, as September melded into October, and Mealey telling me that he was yet to have his first discussion with Aherne concerning that year's Christmas special. I know people who are buying Christmas presents by then.
Anyway, it takes a brave comedian to resist the flattery of a Christmas special, but with some shows it would just seem plain wrong. A Peep Show Christmas special? I don't think so. "Merry Christmas, Malcolm Tucker: The Thick of It Yuletide Extravaganza"? Armando Iannucci has too much self-respect, although if he ever loses it, Tucker would make a terrific Scrooge. A Shameless Christmas special? Actually they've been making those since 2004, when a consignment of dodgy stolen meat led to the Chatsworth state being sealed off by the Army. Most Christmas specials don't have such chutzpah.
In fact just how "special" are Christmas specials? Not very, as a rule. The most successful ones tend not to rely simply on taking the usual characters and plonking paper hats on their heads. Take the two-part 2003 finale of The Office, Ricky Gervais's unexpectedly happy swansong for David Brent. Brent, now a travelling salesman, attends the Wernham Hogg Christmas party with a woman he has just met on an internet dating service – and this intelligent and attractive lady finds Brent funny instead of cringe-making. Such a miracle chimed with the true spirit of Christmas and the episodes won two Baftas.
Gervais and Stephen Merchant decided to kill off their creation with their Christmas special, partly because they didn't think that a full third series was artistically the right thing to do. And Christmas one-offs are a tempting prospect for any sitcom that has perhaps passed its natural life-span, or lost its creators' interest, but can still make a major contribution to the ratings. The last full series of Only Fools and Horses was as long ago as 1991, but Del Boy and Rodney lived on in Christmas specials right up to 2003. The Vicar of Dibley likewise outlived its existence as a full-blown sitcom with a succession of Christmas and New Year episodes (although Gavin & Stacey fans hoping for a similar after-life might be in for a disappointment, as James Corden and Ruth Jones have specifically sworn off any future Christmas specials).
And this semi-retirement, much-loved shows being wheeled out for the big occasions, isn't the only way in which these so-called specials provide a sort of life-after-death – for, dusted down each December, they are the ever-amenable ghosts of TV Christmases past. This holiday alone will not only see the above-mentioned The Office finale from 2003 (Christmas Eve, 9pm Dave), but also the 1974 "Turkey Dinner" episode from Dad's Army (Christmas Day, 8pm BBC2), the 1973 Morecambe and Wise Christmas Show that featured Rudolf Nureyev, Laurence Olivier and André Previn (Boxing Day, 9.10pm BBC2), Knowing Me, Knowing Yule – with Alan Partridge (27 December, 9pm BBC2), a 1985 Terry and June episode in which the couple find themselves sharing a pantomime cow costume (29 December, 8.30pm BBC2) and a 1976 instalment of Are You Being Served? in which the Grace Brothers staff vie to be the in-store Father Christmas. Are you free?
Full of fizz or falling flat? This year's comedy specials
A Grumpy Guide to Christmas
Go on, get it off your chest (vicariously at least) and release your inner Scrooge before the festivities begin in earnest – although you might not go as far as Neil Morrissey, who says he wants to lock himself in the lavatory with a portable TV and some bottles of wine.
When: 23 December 9pm BBC1
It's December 2039 chez the Harpers, and an 80-year-old Ben gets a Christmas gift of a memory eraser that wipes out the previous 20 seconds. That could come in handy for those who find the punchlines in this popular domestic sitcom too corny for words.
When: Christmas Eve, 8pm BBC1
Victoria Wood's Midlife Christmas
Delia Smith, Torvil and Dean and Anton du Beke may look positively C-list compared to the luminaries whom Morecambe and Wise once attracted to their Christmas shows, but there's always Julie Walters as Bo Beaumont from 'Acorn Antiques' and Wood herself as 'Apprentice' sidekick Margaret Mountford.
When: Christmas Eve, 9pm BBC1
The Royle Family: The Golden Egg Cup
Last year's 'The New Sofa' was a major disappointment, but hopefully a one-off aberration. Here, Ralf Little's Antony returns to the bosom of his family in an unlikely scenario that involves the children making a gift of some money to Jim and Barbara.
When: Christmas Day, 9pm BBC1
Gavin & Stacey
The most unseasonal of all this year's Christmas specials takes place during the August bank holiday, when the Essex contingent have decamped to the seaside. In fact, scheduling apart, you'd be hard-pressed to call it a Christmas special at all. The very last episode is on New Year's Day.
When: Christmas Day, 10pm BBC1
Catherine Tate: Nan's Christmas Carol
This is more like it. Back on a seasonal theme, Tate's foul-mouthed and somewhat schizoid cockney OAP takes the Scrooge role in the loosest of loose 'A Christmas Carol' adaptations.
When: Christmas Day, 10.30pm BBC1
Outnumbered – the Christmas Special
Fresh from winning armfuls of British Comedy Awards, Andy Hamilton and Guy Jenkin's ad-lib riposte to 'My Family' is the most hotly anticipated of this year's Christmas specials. Santa visits the Brockman household, as do some burglars.
When: 27 December, 10.30pm BBC1