 "Diplomacy" has been played by mail since 1963, introducing a multi-player aspect to PBM games.Flying Buffalo Inc pioneered the first commercially available PBM game in 1970.A small number of PBM companies followed in the 1970s, with an explosion of hundreds of startup PBM companies in the 1980s at the peak of PBM gaming popularity, many of them small hobby companies—more than 90 percent of which eventually folded.