Robert Frederick Foster (May 31, 1853 – December 25, 1945) of New York City, known as R. F. Foster, was a memory training promoter and the prolific writer of more than 50 nonfiction books. He wrote primarily on the rules of play and methods for successful play of card, dice, and board games. Alan Truscott wrote 20 years after his death that Foster "had been one of the great figures in whist and bridge" for 60 years.
R. F. Foster was born in Edinburgh, Scotland on May 31, 1853, the son of Alexander Frederick and Mary E. Macbrair, and "connected with some of the best families in Great Britain". He was educated as an architect and civil engineer. He emigrated to the United States (probably in 1872) where he engaged in surveying and gold prospecting and then in manufacturing before turning to the memory training and writing businesses in 1893.
Foster married Mary E. Johnson in 1891 and became card editor for the New York Sun in 1895. He filled that position to 1919 when he undertook the same role for the New York Tribune. He was also a columnist for Vanity Fair. The treatise Foster's Complete Hoyle: An Encyclopedia of All the Indoor Games Played at the Present Day, first published in 1897, has been called his great achievement. It provided descriptions and laws of more than 100 indoor games and was revised frequently during his lifetime, then by others after his death. One of his last editions was included in the 1939 New York World's Fair Westinghouse Time Capsule, to be opened in 5000 years.
Having written numerous whist and bridge books by 1935, he was considered "the dean of living bridge authorities". At that time he directed duplicate bridge at the St. George Club in Brooklyn (Hotel St. George). At some time he lived four years in Germany; at another time, "three years in South Africa, where he lectured and taught bridge in sixty-five towns." He crossed the Atlantic 97 times in all.
Foster was a member of several card, athletic, and golf clubs—including Knickerbockers Whist and the Cavendish Club—and a member of the Society of American Magicians. He died December 25, 1945, in Eastham, Massachusetts, survived by one daughter.