The term 'on folly' is a slang expression predominantly used by gang communities, particularly in the Chicago area. To be 'on folly' signifies one's alignment with a life of crime, indicating readiness to engage in illegal activities. For instance, a person who positions themselves strategically with firearms, like 223s, is considered 'on folly.' Similarly, an individual prepared to commit violent acts or attends gatherings with illegal firearms, known colloquially as '30 poppas,' is likewise 'on folly.' This term shares similarities with the expression 'on dummy.'
Folly, in standard English, is defined by the Merriam-Webster Dictionary as a 'lack of good sense or normal prudence and foresight' and refers to 'criminally or tragically foolish actions or conduct.'
Some gang members assert that the term 'folly' serves as a derogatory reference when directed towards members of the Black P Stone gang.