Source: https://www.the-tls.co.uk/articles/willard-price-adventure-books-sam-leith-essay/
In the Introduction to the Encyclopedia of Adventure Fiction, Critic Don D'Ammassa defines the genre as follows:
An adventure is an event or series of events that happens outside the course of the protagonist's ordinary life, usually accompanied by danger, often by physical action. Adventure stories almost always move quickly, and the pace of the plot is at least as important as characterization, setting and other elements of a creative work.
Adventure has been a common theme since the earliest days of written fiction. Indeed, the standard plot of Medieval romances was a series of adventures...
Variations kept the genre alive. From the mid-19th century onwards, when mass literacy grew, adventure became a popular subgenre of fiction. Although not exploited to its fullest, adventure has seen many changes over the years – from being constrained to stories of knights in armor to stories of high-tech espionages...
Adventure fiction often overlaps with other genres, notably war novels, crime novels, sea stories, Robinsonades, spy stories..., science fiction, fantasy... and Westerns. Not all books within these genres are adventures. Adventure fiction takes the setting and premise of these other genres, but the fast-paced plot of an adventure focuses on the actions of the hero within the setting.
Characteristics of Adventure Fiction | Pen & the Pad
Subgenres | Children's Adventure Genre Guide
The Adventure Genre | Children's Literature Classics
Genre Blending: The Romans of Adventure, & the Adventure of Romance | Writers Store
10 Tips & 6 Elements of a Good Adventure Story | The Urban Writers
How to Write an Adventure Story: Creating Amazing Journeys | Now Novel
Tips on Making Your Adventure Story Convincing | CS Lakin: Live Write Thrive
A Closer Look at Cross-Genre Adventure Writing | Freelance Writing
How to Write a Pick-a-Path Story | Hobby Lark