From the back of the book:
For years, legendary gaming icon Colonel Lou Zocchi has sold the esoteric 50-sided die at his convention booths. Now Goodman Games brings you, at long last, fifty fantastic functions for the d50!
This entertaining book contains more than 50 entries describing how to use the d50, ranging from randomized tables to customized game mechanics. This book will ensure everyone at your table can't wait to use their d50!
If you don't have a d50 yet, you can still use the book by rolling D% and diving the result by 2 - but after a glance through this tome you will be motivated to run out and buy your own d50!