patches-own[living] to setup clear-all ask patches [ if random-float 1 < 0.3[ set pcolor white ] set living 0 ] end to go ask patches[ set living count neighbors with [pcolor = black] ] ask patches[ ifelse pcolor = black[ if living > 3 or living < 2[ set pcolor white ] ] [ if living = 3[ set pcolor black ] ] ] end