Oblique Strategies: Over One Hundred Worthwhile Dilemmas by Brian Eno and Peter Schmidt. "Fifth, again slightly revised edition, 2001" stated on one of the two informative cards. This set is complete with 103 dilemma cards and two informative cards (I counted them). In a published 3 1/8" x 4" x 2" box. There is light wear on some of the box edges. Bright gilt lettering on two of the box sides. No previous owner markings. No tears, folds or creases to cards. Not ex-library, not remaindered and not a facsimile reprint. For sale by Jon Wobber, bookseller since 1978. sIL20a
"In 1970, Peter Schmidt created "The Thoughts Behind the Thoughts", a box containing 55 sentences letterpress printed onto disused prints that accumulated in his studio, which is still in Eno's possession. Eno, who had known Schmidt since the late 1960s, had been pursuing a similar project himself, which he had handwritten onto a number of bamboo cards and given the name "Oblique Strategies" in 1974. There was a significant overlap between the two projects, and so, in late 1974, Schmidt and Eno combined them into a single pack of cards and offered them for general sale. The set went through three limited edition printings before Schmidt suddenly died in early 1980, after which the card decks became rather rare and expensive. Sixteen years later software pioneer Peter Norton convinced Eno to let him create a fourth edition as Christmas gifts for his friends (not for sale, although they occasionally come up at auction). Eno's decision to revisit the cards and his collaboration with Norton in revising them is described in detail in his 1996 book A Year with Swollen Appendices. With public interest in the cards undiminished, in 2001 Eno once again produced a new set of Oblique Strategies cards. The number and content of the cards vary according to the edition. In May 2013 a limited edition of 500 boxes, in burgundy rather than black, was issued.
Each card contains a gnomic suggestion, aphorism or remark which can be used to break a deadlock or dilemma situation. A few are specific to music composition; others are more general." - Wikipedia
I recommend reading the Wikipedia piece on this set. There is more information there than I can really put on this site. - JW