Warning: Wikipedia contains spoilers
The book takes Luke's style to its logical conclusion, as the entire book is made up of sections taken from other, fictional books. The preface to the book claims that it was written in Deya, Majorca, in 2326. According to the book, an entire industry has grown up publishing books about a Montauk named Wim - including The Gospel According to Luke (Luke Forth, not Luke Rhinehart) and the screenplay of a movie. The screenplay is possibly in there as a result of Luke Rhinehart's continuing frustration in trying to get The Dice Man turned into a good movie. Adventures of Wim, then, is an effort to create a new interpretation of the story of Wim, drawing on the many previous efforts, and so providing a multi-faceted and whimsical account of 'one of the greatest figures in the 20th and 21st Century'.
A boy is born of a virgin mother and is named "Wim" (in Adventures of Wim) or "Whim" (in The Book of the Die and Whim): Montauk for "Wave Rider". He is pronounced to be the saviour of the Montauk nation by his tribe's navigator, and educated in their ways. Sadly, the humans steal him away and attempt to educate him in more useful skills, such as American Football. Wim, also known as "He of Many Chances", proves to be an inefficient saviour, as God sends him on a quest for Ultimate Truth. This does not seem to be something that will benefit his tribe terribly, but the navigator isn't one to stare down the barrel of a lightning gun, and sends him on his way. After a long and arduous search, Wim finds ultimate truth (in a potato), and with it the cure for the sickness of the human condition.
There's a lot of philosophy in this book, and it's a more open view than in previous books. The book ties in with the views of The Dice Man, but in a softer and more accepting way, and with more paths to enlightenment. It's also the funniest book Luke has written to date. If that's not enough, then you should definitely read this book to learn how to do that perfect basketball hook shot.
The various versions of the book are: