▁As ▁a ▁result , ▁fant astic ▁mut ations ▁such ▁as ▁extra ▁lim bs , ▁super ▁strength , ▁and ▁psych ic ▁powers ▁are ▁relatively ▁common . ▁ ▁( Random ▁tables ▁of ▁such ▁impro b able ▁mut ations ▁are ▁a ▁hall mark ▁of ▁every ▁edition ▁of ▁G amma ▁World .) ▁ ▁Many ▁animals ▁and ▁plants ▁are ▁sent ient , ▁semi - c ivil ized ▁species ▁compet ing ▁with ▁surv iving ▁humans . ▁ ▁Both ▁humans ▁and ▁non - hum ans ▁have ▁lost ▁most ▁knowledge ▁of ▁the ▁pre - war ▁humans , ▁whom ▁G amma ▁World ' s ▁inhabitants ▁refer ▁to ▁as ▁" the ▁An ci ents ". ▁ ▁The ▁only ▁group ▁with ▁significant ▁knowledge ▁of ▁the ▁An ci ents ▁are ▁isolated ▁rob ots ▁and ▁other ▁artificial ▁intellig ences ▁that ▁surv ived ▁the ▁war — though ▁these ▁machines ▁tend ▁to ▁be ▁dam aged , ▁in ▁ill ▁repair , ▁or ▁host ile ▁to ▁organ ic ▁be ings . ▁ ▁G amma ▁World ▁player ▁characters ▁include ▁un mut ated ▁humans ▁( re ferred ▁to ▁as ▁" P ure ▁St rain ▁Hum ans " ▁in ▁most ▁ed itions ), ▁mut ated ▁humans , ▁sent ient ▁animals ▁or ▁plants , ▁and ▁android s . ▁ ▁Char acters ▁explore ▁An cient ▁ru ins ▁and ▁strange ▁post - ap oc aly ptic ▁soci eties ▁to ▁gain ▁knowledge ▁of ▁the ▁An ci ents ▁and ▁social ▁status ▁for ▁themselves . ▁ ▁Common ▁advent ure ▁them es ▁involve ▁protect ing ▁frag ile ▁post - ap ocal yp se ▁soci eties , ▁retr ieving ▁An cient