Perhaps that experience put me off seasonal adventures. I've never deliberately written one, and I tend to avoid playing them. However the folks at Penny-Arcade clearly don't share my point of view. Sounds like they had a lot of fun with the central idea, and it probably helped that the situation as described wasn't all combat all the time. Chaosium also produce a seasonal adventure once a year, but their holiday pick isn't quite as jolly. I suppose that's to be expected really, but M.R. James managed a Christmas ghost story or two, and he was carrying on a fine old tradition which the BBC occasionally resurrects. Winter festivals often have the theme of light versus dark; the seasons are turning, the nights are getting colder, but there is the promise of spring to come. The land is changing from an infertile, dead panorama to warmth and life, and the winter festivals honor the last gasp of the old with a celebration of the new, marking the passage of the winter solstice.
Ghost stories are particularly apt, given that they too are about the cold hand of the past interfering with the bustling present day, possibly even smothering hopes of the future. There is always the threat of death in the coldest months, even today, and when Dickens wrote his Christmas Carol the threat was much more acute that it is now. Of course, Dickens ends his tale on a cheerful note; not so The Little Match Girl, Anderson's tale written at the same period. Anderson's story has a mix of hard-nosed realism and sentimentality that would have appealed to his readers, but I'm not certain an author could get away with Anderson's version these days. Hogfather's retelling of the same story is probably closer to the modern point of view.
Personally I feel that a seasonal RPG story, if it's to work well, needs to rely less on the season and more on the story. Ravenous and deadly plum puddings make for a funny scene, but you oughtn't dump half a ton of slapstick and Christmas in-jokes and expect everyone to have a good time. There needs to be a solid backbone to your plot, preferably one that doesn't rely exclusively on seasonal references. Moreover if it's to be a ghost story, then let it be a ghost story. M.R. James once gave advice on this point:
Two ingredients most valuable in the concocting of a ghost story are, to me, the atmosphere and the nicely managed crescendo.… Let us, then, be introduced to the actors in a placid way; let us see them going about their ordinary business, undisturbed by forebodings, pleased with their surroundings; and into this calm environment let the ominous thing put out its head, unobtrusively at first, and then more insistently, until it holds the stage.
In other words you can't just leap in with the grue and paint the surroundings all over red in the very first scene. The background is important, and it needs to start in as mundane a setting as possible. Dicken's Signal-Man is a case in point: to Dickens' readers, nothing could have been more familiar than a railway junction, and deaths on the line were sufficiently common to be on everyone's mind. James does much the same thing, by setting his tales in ordinary places: boarding houses, churches, buses, farmer's fields, seaside resorts, all places that his readers would have known about, probably from first-hand experience. These settings were the everyday of their lives. Some of them seem antique now; we don't go to church as often as James' readers would have done, the boarding houses he knew have all but vanished, and bus conductors don't talk like that any more, if indeed they ever did. Yet at the time they would have fit right in, and therein lies the key. Make the setting as familiar as possible, and the players will fill in the blanks with their own experience.
The second key ingredient is the build-up, unobtrusive at first, then building to a crescendo. Something in the background needs to be twisted, to take on a significance that will later become critical. Again going back to James, consider what effects he achieved with a bed sheet, a church stall, or a doll's house, to name three. All things that the reader and the characters would have found perfectly unremarkable, made remarkable by force of circumstance. Fact needs to pile upon fact until nobody can pretend that it's all coincidence, that it can be explained away.
With all that in mind, consider the following ghost story nugget, written with Trail of Cthulhu rules:
Police Box, SohoThis is a solid concrete structure, painted blue, with a teak door. A light on the top of the structure, when lit, warns constables that they ought to contact the station immediately. Inside there is a stool, a table, cleaning equipment, a fire extinguisher, and a small electric heater, in addition to the police telephone. As the structure is made entirely of concrete, it is cold and damp at the best of times, and bitterly cold in winter. The electric heater seldom works properly. The desk and stool are sturdy but cheap, and not particularly comfortable.
Station gossip has it that a young constable actually froze to death inside the Box several years ago, though the rumour is third or fourth hand at best. Nobody can actually claim to have worked with the constable or found the body. That said, the rumour is persistent, and the Box is so unpopular that staying in the Box for an hour, at night, is something of a challenge, a rite of passage that the older men make the younger ones go through. The honour won is all the greater if the challenged copper undertakes the vigil during the winter. The ‘frozen constable’ story gained unexpected credence only last November, when a probationer caught frostbite after twenty minutes inside. He risked losing some of his fingers, but in the end was fully restored to health and rapidly transferred to a different station, far away. That incident does have a few witnesses, including the Sergeant who pulled the lad out of the box before he froze altogether, but none of them are willing to talk about it to outsiders and the Sergeant won’t talk about it at all to anyone. A man’s hard-earned promotion is not lightly risked, and he doesn’t want his superiors thinking he might be batty or a drunkard.
The Knowledge. That corner of Soho has always had a nasty reputation. There used to be a Salvation Army hostel right across from the Box, which had four penny coffins: the sort of place that let the indigent sleep in a box with a tarpaulin over it for four pennies. They had to close the hostel down in 1902, after eight of their guests froze to death, all in the same night. In 1814, the year of the last Thames Frost Fair, eighteen people died, most of them over a four day freeze. Among the eighteen was a soldier who, when last seen, was leaving a public house and intended to walk down the street to visit a friend, perhaps a five minute stroll at most. He froze before he got half-way to his destination.
Anthropology. During winter, and especially if it’s a hard winter, the people living and working roundabout always wear orange, or have an orange keepsake prominently displayed, like a headscarf or a handkerchief knotted about their left wrist. Most of them couldn’t tell you why they do it, except that it’s supposed to be lucky. However according to legend orange is Jack Frost’s favourite colour; he paints the leaves with it, to make them beautiful. Anyone wearing orange will get Jack Frost’s favour, and perhaps then he will leave them alone.
Cop Talk. It’s difficult enough to find a copper in Soho at the best of times. It’s damn near impossible to find one in winter, and unless it’s done on a bet there isn’t a policeman born will spend even a minute in the Box. That, and if one happens to spot you hanging round near the Box, you’d better step lively, or you’ll get a thump round the ear’ole if you’re lucky, and a night in the cells if you’re not. Drunk and disorderly will be the charge, whether you’d had a couple or was as sober as a judge. The older coppers wear orange too, most of them, same as the others on the street. They’re just more discreet about it, is all.Potential antagonist:
Cold One. Abilities: Athletics 11, Health 9, Scuffling 10. Magic: 8. Hit Threshold: 4. Stealth: +3 (snow). Weapon: Frost attack (-2), to Health, Fleeing and Athletics, on successful Scuffling. Armour: immune to physical damage, fire does +1 but any flame smaller than a bonfire extinguishes on contact. Stability: +1. Special: awful howling noise. Could, at a distance, be mistaken for a police officer; the shape of the ‘head’ and upper body is very like an 1850s peeler, including the top hat and collar.
Fewer things are more mundane than a city street, with people bustling to and fro and a copper on the corner trying to keep warm. The Police Box is slightly less familiar to a modern audience, but anyone who's ever watched Doctor Who knows what they look like, and pictures are easily had. From there it's the slow, remorseless build-up, and I find the Trail clue structure helps with this, as players pile clue upon clue until revelation is inescapable. Jack Frost nipping at their nose - or snuffing out their lives . . .