The adventure in Robinson Crusoe emerges through an exciting plot that pits man against nature. After going to sea against the advice of his sober-minded parents and surviving many adventures, Crusoe becomes the sole survivor of a dramatic shipwreck. Finding himself all alone on an island, he realizes the odds are stacked against him.
More than any more exalted themes, the story of exactly how a lone man manages to stay alive and thrive on an untamed island has captured imaginations for many generations. We identify with Crusoe because, like us, he is an ordinary human. The novel has no supernatural elements: no magical fairies or sprites are going to come to save him. We put ourselves in his shoes and keep reading to find out how Crusoe will use nothing but his wits and hard work to beat the odds. The wealth of detail that Defoe offers about what Crusoe exactly does to survive makes the story believable and interesting.
Later, as Crusoe settles in and his mere survival is no longer a question, new adventure comes as he witnesses native cannibals from a neighboring island landing on the shores of "his" island. This adds a new level of adventure, and we thrill as Crusoe saves Friday.
Plot is important, and even though Crusoe spends much of the novel alone, there is always something going on to catch our interest. The message or theme of the adventure is never to give up, because you don't know what you have inside you or what the world (or God, in terms of how Crusoe understands his experiences) has in store for you until you put your all into the struggle for life.