The Game of X

From Author Wars - https://authorwars.com/publications/the-game-of-x-640879.html

Overview:

Title: The Game of X
Author: Robert Sheckley
Year: 1966
Publisher: Dell
Price: C$0.60
Pages: 159
Binding: Paperback
Type: Novel
Title Reference: The Game of X
Notes:
• "First Dell printing—October, 1966"; no number line • "Cover illustration: Crowley" on back cover, no visible signature on the artwork