Horace Walpole's style in The Castle of Otranto is impassioned, picturesque, and sometimes extravagant. The author's sentences are often long and complex, reflecting the patchwork of history that affects the actions of the characters. The novel also comes with two conflicting and somewhat bizarre Prefaces, which were published respectively with the First and Second Editions. In these, the author situates The Castle of Otranto as a frame story, and supplies an imaginary origin, author, and translator for the novel. He then recants this in an explanation of his aims in doing so, and defends himself from critics by comparing his work to Shakespeare. Walpole was keen to have the novel be read in exactly the way he had planned.
This intention is also reflected in Walpole's writing. His style gluts the reader with a huge amount of data, leaving little to interpretation. Like many of the Gothic novels which follow it, The Castle of Otranto is dense with sensory language and very detailed. Short descriptive passages are interspersed with plot exposition by the narrator and intense and lengthy sections of dialogue. It's notable, though, that Walpole makes minimal if any use of simile, which he declares is intentional in the First Edition Preface. The style of the novel is deliberately fast-paced, as Walpole explains:
There is no bombast, no similes, flowers, digressions, or unnecessary descriptions. Every thing tends directly to the catastrophe. Never is the reader’s attention relaxed. The rules of the drama are almost observed throughout the conduct of the piece. The characters are well drawn, and still better maintained. Terror, the author’s principal engine, prevents the story from ever languishing; and it is so often contrasted by pity, that the mind is kept up in a constant vicissitude of interesting passions.
In his goal to make "every thing" point the reader toward the "catastrophe," Walpole devotes a lot of the novel to the explanation of The Castle of Otranto's interlocking and complicated storylines. The rhythm of the five chapters is lightning-fast and almost feverish, as Walpole packs in event after event to keep the story from "ever languishing."