3 , ▁when ▁American ▁anti - mon opol ist ▁L iz zie ▁Mag ie ▁created ▁a ▁game ▁which ▁she ▁hoped ▁would ▁explain ▁the ▁single ▁tax ▁theory ▁of ▁Henry ▁George . ▁It ▁was ▁intended ▁as ▁an ▁educational ▁tool ▁to ▁illustrate ▁the ▁negative ▁aspects ▁of ▁concentr ating ▁land ▁in ▁private ▁mon opol ies . ▁She ▁took ▁out ▁a ▁pat ent ▁in ▁ 1 9 0 4 . ▁Her ▁game , ▁The ▁Land l ord ' s ▁Game , ▁was ▁self - pub lished , ▁beginning ▁in ▁ 1 9 0 6 . ▁ ▁Mag ie ▁created ▁two ▁sets ▁of ▁rules : ▁an ▁anti - mon opol ist ▁set ▁in ▁which ▁all ▁were ▁reward ed ▁when ▁wealth ▁was ▁created , ▁and ▁a ▁mon opol ist ▁set ▁in ▁which ▁the ▁goal ▁was ▁to ▁create ▁mon opol ies ▁and ▁cr ush ▁oppon ents . ▁ ▁Several ▁variant ▁board ▁games , ▁based ▁on ▁her ▁concept , ▁were ▁developed ▁from ▁ 1 9 0 6 ▁through ▁the ▁ 1 9 3 0 s ; ▁they ▁involved ▁both ▁the ▁process ▁of ▁bu ying ▁land ▁for ▁its ▁development ▁and ▁the ▁sale ▁of ▁any ▁und e velop ed ▁property . ▁Card board ▁houses ▁were ▁added ▁and ▁r ents ▁increased ▁as ▁they ▁were ▁added ▁to ▁a ▁property . ▁Mag ie ▁pat ented ▁the ▁game ▁again ▁in ▁ 1 9 2 3 . ▁ ▁According ▁to ▁an ▁advert is ement ▁placed ▁in ▁The ▁Christian ▁Science ▁Mon itor , ▁Charles ▁Tod d ▁of ▁Philadelphia ▁re called ▁the ▁day ▁in ▁ 1 9 3 2 ▁when ▁his