▁the ▁G amma ▁World ▁setting ▁from ▁W OT C ▁in ▁order ▁to ▁produce ▁a ▁sixth ▁version ▁of ▁the ▁game . ▁S SS ' s ▁version ▁of ▁the ▁game , ▁which ▁reached ▁the ▁market ▁in ▁ 2 0 0 3 , ▁used ▁the ▁d 2 0 ▁Modern ▁system , ▁and ▁m im icked ▁D & D ' s ▁" three ▁core ▁book " ▁model ▁with ▁three ▁hard cover ▁manual s : Gamma ▁World ▁Player ' s ▁Hand book ▁by ▁Bruce ▁B augh , ▁Ian ▁Ell er , ▁Mik ko ▁R aut ala ht i , ▁and ▁Geoff ▁Sk ell ams Gamma ▁World ▁Game ▁Master ' s ▁Guide ▁by ▁Bruce ▁B augh , ▁Werner ▁H ager , ▁L izard , ▁and ▁Doug ▁Og les by Gamma ▁World ▁Mach ines ▁and ▁Mut ants ▁by ▁David ▁Bol ack , ▁G are th ▁Han ra han , ▁Patrick ▁O ' D uff y , ▁and ▁Ch uck ▁Wend ig ▁ ▁S word ▁& ▁Sor c ery ▁Studios ▁also ▁published ▁three ▁paper back ▁supp lement s ▁for ▁the ▁d 2 0 ▁version ▁of ▁G amma ▁World : Gamma ▁World ▁Bey ond ▁the ▁Hor izon ▁by ▁Ellen ▁K iley Gamma ▁World ▁C rypt ic ▁Al li ances ▁and ▁Un known ▁En em ies ▁by ▁O wen ▁K . C . ▁Steph ens , ▁Ale j andro ▁Mel chor , ▁and ▁Geoff ▁Sk ell ams Gamma ▁World ▁Out ▁of ▁the ▁V ault s ▁by ▁James ▁Mal isz ew ski , ▁John ▁S ne ad , ▁and ▁Ellen ▁P . ▁K iley