The most popular murder mystery weekends have at least one thing in common: custom-written scenarios, geared to the geographic location and often to the interests of the guests/sponsors.

In the case of Mohonk Mountain House, a rambling Victorian-era resort hotel outside New Paltz, N.Y., the scripts are done by mystery writer Donald E. Westlake (The Hot Rock, The Bank Shot, The Hunter, High Adventure).

''High Jinx,'' Westlake's scenario for two mystery weekends last March, had the same characters and plot, but a different solution each weekend:

It's 1938 and people have come to the ''Hotel Kuckkuckuhr, high atop Mount Melblanc in the Swiss Alps,'' to escape the gathering stormclouds spreading across the Continent.

A blizzard, with attendant avalanches, is raging outside. Inside there is a different storm, one marked by rampant foreign intrigue. People spying on one another. Abundant secrets. And an uninvited guest . . .

Murder.

The victim: Kurt Krauss, the most feared and hated critic on the Continent, whose most casual sneer can close a play, damn a book, destroy a career. He has at last met a critic even harsher than he.

Hotel guests worked in teams to solve the mystery. Interspersed with their sleuthing efforts were talks by Martin Cruz Smith (Gorky Park), Gavin Lyall (The Most Dangerous Game, Midnight Plus One), London Sunday Observer reporter-columnist Katharine Whitehorn and financier-author Edward A. Pollitz Jr. (The Forty-First Thief and The 2000% Rule).

Late-night movies, ''not unrelated to the story line,'' were screened and discussed, and a full-scale masked ball featured music by musicians conveniently snowbound with the paying guests and suspect characters.

Rates for these particular weekends ran from $518 to $701, double occupancy, and $269 to $439, single occupancy. The charges covered three nights's lodging, nine meals, program fee, gratuity and tax.