Chain Reaction is an American game show created by Bob Stewart, in which players compete to form chains composed of two-word phrases.The show has aired four separate runs: Bill Cullen hosted the original series on NBC from January 14 to June 20, 1980. The second version aired on the USA Network from September 29, 1986 to December 27, 1991 and was hosted first by Blake Emmons and later by Geoff Edwards. A third version on GSN aired from August 1, 2006 until June 9, 2007, hosted by Dylan Lane.