Ferdinand Maack (1861–1930) was a German doctor, inventor and occultist. He invented Raumschach, the classic 3D chess game, first described by him in the Frankfurter Zeitung in 1907.[1][2][3] He promoted the game with demonstrations, articles, specialist magazines[a] and several books.[b] He founded the Hamburg Raumschach Club in 1919, which remained active until World War II.