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.    He promoted the game with demonstrations, articles, specialist magazines (eg Raumschach ) and several books. [A] He founded the Hamburg Raumschach Club in 1919, which remained active until World War II.
- Jump up^ Das Schachraumspiel: Dreidimensionales Schachspiel(printed 1907); Spielregeln zum Raumschach(1913); Raumschach: Einführung in die Spielpraxis(1919). 
- Jump up^ Hooper & Whyld (1987), pp. 351-52
- Jump up^ Pritchard (1994), pp. 305-07
- Jump up^ Pritchard (2007), p. 230
- Jump up^ Dickins (1971), p. 16