[2][3] He is best known for co-authorship (with John Conway and Elwyn Berlekamp) of Winning Ways for your Mathematical Plays and authorship of Unsolved Problems in Number Theory.

[10] Although his parents strongly advised against it, Guy decided to become a teacher and got a teaching diploma at the University of Birmingham.

He met his future wife, Nancy Louise Thirian, through her brother Michael, who was a fellow scholarship winner at Gonville and Caius.

In November 1942, Guy received an emergency commission in the Meteorological Branch of the Royal Air Force, with the rank of flight lieutenant.

While in Iceland, he did some glacier travel, skiing, and mountain climbing, marking the beginning of another long love affair, this one with snow and ice.

[12] When Guy returned to England after the war, he went back to teaching, this time at Stockport Grammar School, but stayed only two years.

Guy said that they gave him the degree out of embarrassment, although the university stated that "his extensive research efforts and prolific writings in the field of number theory and combinatorics have added much to the underpinnings of game theory and its extensive application to many forms of human activity.

"[19] Guy and his wife Louise (who died in 2010) remained very committed to mountain hiking and environmentalism even in their later years.

[20] In turn, the Alpine Club has honoured them by building the Louise and Richard Guy Hut near the base of Mont des Poilus.

[33] In a career that spans eight decades he wrote or co-authored more than a dozen books and collaborated with some of the most important mathematicians of the twentieth century.

[34] Paul Erdős, John H. Conway, Donald Knuth, and Martin Gardner were among his collaborators, as were Elwyn Berlekamp, John L. Selfridge, Kenneth Falconer, Frank Harary, Lee Sallows, Gerhard Ringel, Béla Bollobás, C. B. Lacampagne, Bruce Sagan, and Neil Sloane.

He collaborated with Berlekamp and Conway on two volumes of Winning Ways, which Martin Gardner described in 1998 as "the greatest contribution to recreational mathematics in this century".

[41][42] Guy was considered briefly as a replacement for Gardner when the latter retired from the Mathematical Games column at Scientific American.

[46] To mark his 100th birthday friends and colleagues organised a celebration of his life and a tribute song and video was released by Gathering 4 Gardner.