New York: Ballantine Books, 1970. First edition. First edition, first printing. Signed by Larry Niven on the title page in black ink. [viii], 342, [2] pp. Bound in publisher's wraps. Fine, sharp and unread. A lovely signed copy of the Hugo and Nebula Award-winning novel, quite uncommon in such nice condition for a paperback original. Later editions corrected the opening chapter, which had Louis Wu teleporting eastward around the Earth in order to extend his birthday, which would have made him arrive instead on the following day. In his introduction to The Ringworld Engineers, the author wrote, "If you own a first paperback edition of Ringworld, it's the one with the mistakes in it. It's worth money.