Saki (H. H. Munro) succeeds in his fiction because of his inimitable blend of satire, irony, startling endings, clever dialogue, sparkling wit, psychological insight, unconventional settings, mystery, and sometimes even horror. 

While Saki is almost always a satirist, his satire is not biting; rather it seems more a practical joke upon a character of the narrative rather than an invective against the social class Sakicriticizes.  In his short story, "The Mouse," for instance, Theodoric Voler has been brought up in a society that has screened him from "the coarser realities of life."  His fastidious nature is satirzed as part of the Ewardian society which Saki often ridicules; however, the surprise ending seems more a joke on Voler himself than a criticism of his society. Likewise, in "Dusk," the satirization of the cynical Gortsby who feels himself better than the others who come to sit in the park at twilight, ends with an ironic twist that again sharply humorizes Gortsby's character.

"The Interlopers" is another story that is socially satiric as well as psychologically insightful.  Two Russian aristocrats hold each other in enmity because of an inherited feud over a parcel of land.  As they unexpectedly encounter each other one night in the forest, a sudden storm pinions them under the branches of a huge beech tree. Ironically, with death hovering over them, they realize the foolishness of their feud and resolve to be good neighbors after they are rescued by their men who will search for them.  But, when they think they hear men shouting, one of them laughs hollowly, and tells the other that wolves are coming instead.

Saki's writing is certainly clever, socially satiric, and surprising; with its unconventionalities, there is little obeisance for the rules of realism.

What is Saki's writing style?

Saki's written style is perfectly matched to his choice of settings. He often sets his stories in the kind of respectable social environments with which he was all-too familiar. One thinks of the big Edwardian country house in "The Open Window" or the British House of Commons, where Arlington Stringham makes his fateful joke in "The Jesting of Arlington Stringham."

These settings allow Saki to satirize certain elements of contemporary, upper-class English society, using the irony which is his stock-in-trade to devastating effect. There's no trace of sentimentality in Saki's written style; this makes his withering criticism of society's numerous hypocrisies all the more effective, and his famous twist endings just that little bit more powerful.

There's nothing ostensibly horrific about Saki's stories, but the detached, ironic prose does induce a certain unease in the reader. We know that something unpleasant's about to happen to one or more of the characters, but we don't know quite what. A less talented writer would've adopted a more lurid written style, making the horror of the situation more explicit, and therefore much less subtle or effective.