Riverdale's executive producer is someone other than Greg Berlanti.
Sean Punch -LRB- born July 27 , 1967 -RRB- is a Canadian writer and game designer .. writer. writer. game designer. game designer. He is the author of the fourth edition of the GURPS role-playing game .. GURPS. GURPS. role-playing game. role-playing game. Before he turned to writing he was a student of particle physics .. particle physics. particle physics