FILE - In this March 7, 2010 file photo, Don Rickles arrives at the Vanity Fair Oscar party in West Hollywood, Calif. Rickles died Thursday, April 6, 2017, of kidney failure at his Los Angeles home. He was 90. (AP Photo/Peter Kramer, File)

Rickles patented a confrontational style that stand-up performers still emulate, but one that kept him on the right side of trouble. He managed to shock his audiences without cutting social commentary or truly personal self-criticism. He operated under a code as old the Borscht Belt: Go far — ethnic jokes, sex jokes, ribbing Carson for his many marriages — but make sure everyone knows it’s for fun.