Paterson, 40, has written filmscripts (unproduced), an adult play, Mr Government, (resounding flop) plus, years ago, a few short plays for Glasgow’s TAG Theatre to tour schools. These include The Secret Voice, the story of a schoolphobic’s dangerous retreat into a private world with an imaginary companion who becomes increasingly threatening until, just in time, the protagonist emerges into acceptance of society, school and responsibility. It resembles, uncannily closely, Ayckbourn’s later Invisible Friends.

In several ways Secret Voice also resembles the work for which Paterson has become acclaimed in northern climes, the series of six (to date) Christmas plays which began in 1981 with Merlin the Magnificent. Commissioned by Giles Havergal for the Citizens Theatre in Glasgow, it is a Scottish feather of rare plumage in that internationalist theatre’s cap.

Those early Glasgow commissions bore further fruit when a schools’ show Ape Talk was expanded into a Christmas show for Edinburgh’s Royal Lyceum Theatre as Shinda, The Magic Ape. One title further on, the play is now known as Granny and the Gorilla and, like Merlin, it is not on show this year. But the other four all are. You can choose between Cinderella in Manchester, The Snow Queen straight in Newcastle upon Tyne or freely adapted in Leeds, Beauty and the Beast in Dundee or The Princess and the Goblin in Edinburgh. This is based on George MacDonald’s Scottish classic, a precursor of Lewis Carroll’s Alice, only, claims Paterson, superior for having more of a heart.

Such a line up is quite usual for Paterson. Apart from Manchester, where his work has come with Benjamin Twist’s arrival as artistic director at Contact Theatre, all these places are frequent Paterson patrons. Partly because his plays fulfil that basic requirement of the Christmas show - box-office boosting public appeal. But also because directors such as Hugh Hodgart in Dundee and Edinburgh, Neil Murray in Newcastle and Michael Birch at West Yorkshire Playhouse find a welcoming honesty and depth in them.

A Paterson play is likely to be built on this pattern: after a possible glimpse of a forlorn heroine - Isabella, the Cinderella figure mourning by the tree at her mother’s graveside, or Irene in The Princess and the Goblin lamenting her lack of freedom to explore outside her palace - we meet a Witch or witch substitute. This villain expresses deep hatred of children, detecting them as a horrid smell in the audience. They engage in the familiar panto exchange. So, the team of warty Goblins: “We’re bigger, we’re braver, we’re better than you! Oh yes we are”. They will reveal some fiendish plot which may involve a plan of global conquest, like the Snow Queen’s wish to banish the sun (so evil is this character, Paterson holds her back from the familiarity of the Oh yesOh no exchange, reserving it for her sidekick Cobweb Spider later on). Whatever the plan, it will involve gaining power over the innocent.

Heroine meets young male friend, probably of lower social class, only to be separated. Crackjaw whisks off Martin, the new companion to the much put upon Beauty. The Snow Queen splinters Kay’s heart and abducts him from Gerda and her Gran. Cinderella is different; here, Isabella is punished by banishment to the kitchen where she meets a friend, the prisoner Callum.

Two worlds, of light and dark, are introduced (again, Cinderella varies the pattern as the “dark” kitchen proves friendly and warm at last). More forbidding dark places include the Snow Queen’s ice palace “at the top of the world” and the Goblins’ troll-like cave kingdom. These contrast the busy everyday world of palace or castle (and parallel the claustrophobic bedroom in Secret Voice). The heroine sets off on a perilous journey, on behalf of another character - Beauty for her father, Gerda to rescue Kay. She will have two protectors - the audience and an animal, big and furry. This may, like Cinderella’s canine Black Douglas or Fannon the dragon in The Princess and the Goblins, initially be thought fearsome, but will soon be revealed as innately cuddly and kind.

There will be attempts to prevent the heroine’s journey - Beauty’s ugly sisters trick her into delaying her return to Beast, the greedy king’s daughter and the Robber Girl in Snow Queen both hold Gerda prisoner. Eventually, heroine and hero will be reunited and may set off together over the mountains on a new journey together.

Such a description sounds schematic but Paterson has much variety of incident. His characters are individuals too, though four groups emerge. The heroine is tough, resourceful and generous, though she will be brought near the point of despair by the villains, most vividly in The Princess and the Goblins where the latter try to force tears from Princess Irene to make a powerful evil potion. The hero will be honest and strong, whether he aids the heroine or, like Kay, needs her help to show his good qualities.

The big villains - Crackjaw, Snow Queen, Isabella’s evil stepmother Claudia - seem invincible for much of the action, turning up to block the heroine’s path just as all seemed well at last. In the end the force of good will destroy evil - Crackjaw is sucked back down the magic well she had escaped from. Often the audience takes a choral hand in effecting this ultimate defeat; their cries of “stay” help Kay withstand the Snow Queen’s last spell.

Then there are the lesser villains, who may be forced into the service of evil. Paterson recalls their origin from schooldays. “I wasn’t a bully, or bullied, but I recall seeing what went on in the playground, staying on the right side of the tough nuts”.

Fathers tend to be well-meaning but ineffectual, perhaps blinded by evil as is Isabella’s through sexual infatuation for the evil Claudia. Mothers are different. Often dead, they return as does Isabella’s, in the form of fairy godmother, to provide moral and spiritual strength, “the love you had from your mother before you were conscious of it”. The role might be taken on by another maternal figure; Gerda’s Gran, who adopts the “Boy the sea gave to the shore” Kay, or Irene’s Great Great Grandmother, discovered by her in a remote turret of the castle.

Here is a clear metaphor; the internal searching that brings Irene to a source of strength. Talk to Stuart Paterson or his regular directors and two words recur, “fable” and “metaphor”. They are what make his plays so different from the pantomimes he loathes (it’s about the only dramatic subject which enrages him). “Pantomime celebrates wealth and marriage. Yet Cinderella, for example, is about finding your inner self. That’s what the marriage signifies”. But you wouldn’t guess it from panto. “Only in Great Britain could something as outworn, faded and tacky as pantomime survive”. And that’s before we reach the casting. Paterson admits he would pay to see a genius like Stanley Baxter or Rikki Fulton on stage, but not the soap stars and sports personalities so often dished up.

Directors also celebrate Paterson’s honesty in presenting a child’s world. His characters chafe at the restrictions adults place on them, but a character like Irene’s protective Nurse Lootie has a point. The Goblins are out there, waiting to snatch her. “Children need optimism”, says Paterson, “but must be told life out there is difficult, serious, dangerous”. Community and sharing are his other big themes. Part of the heroine’s sadness at the beginning is likely to be loneliness. If major villains want power, lesser ones are likely to be materialistic. In The Snow Queen the Robber Girl wants Gerda as a friend but treats her like a possession. Spoiled by her over-indulgent, drunken Robber Queen mother she ties Gerda up and cannot believe Gerda does not also carry a knife to guard her belongings. Selfishness and possessiveness have to be overcome before the good can be found in such morally mixed characters. Typically, the audience is included in the commonwealth of happiness by actively helping the action to its conclusion.

What of that other audience involvement, the panto hiss and boo? Though Paterson believes panto, far from the subversive claims made for it, is deeply reactionary, he is all in favour of fun. “It is as important (in Cinderella) to laugh at a dog peeing into the cake icing the ugly sisters will consume as to have the poetic image of the graveside tree”. His plays are hugely, sometimes vulgarly funny. And like any potential classic author, he already has his wilder interpreters; Michael Birch at Leeds takes the plays from the proscenium picture-frame he believes is in the writer’s mind and shoves them amid a floor-seated crowd. Birch also believes the scripts lose their irony and rhetoric in English accents so freely adapts: this year’s Snow Queen is set on a railway near coal heaps during a vicious modern war - the devil’s mirror is a gleaming rocket.

Though he hasn’t seen that yet, Stuart Paterson is content for directors to adapt, so long as the result works theatre’s magic and captures the imagination. No wonder he believes that The Tempest, with its mix of magic, monsters, music and young lovers, is the ideal children’s story. Unsentimental, forceful, poetic and comic, his own imagination-grabbing tales work this wonder: that through the darkness emerge young people who gain power by their generosity and companionship, a power that spreads to their audience for whom each New Year brings its fresh darknesses and hopes.

This year’s productions: Beauty and the Beast, Dundee Rep Theatre, to January 14 (0382 23530), Cinderella, Contact Theatre, Manchester, to January 14 (061 274 4400), The Princess and the Goblin, Royal Lyceum, Edinburgh, to January 7 (031 229 9697), The Snow Queen, Newcastle Playhouse, to January 7 (091 230 5151), The Snow Queen, adapted by Michael Birch, Courtyard Theatre, West Yorkshire Playhouse, Leeds, to January 14 (0532 442111)