Franchise-chaser Robert Downey Jr has inked a deal with in-demand screenwriter Marc Guggenheim (“Green Lantern”) to pen his big-screen “Perry Mason” reboot.

Though Mason originated in the pages of the Erle Stanley Gardner books, the lawyer character claimed fame as the central character in a 1950′s/60′s TV series that starred Raymond Burr.

Downey’s film, set up at Warner where he and wife Susan will produce said offering, will be set in the 1930′s – as per the original books, says THR.

Guggenheim’s seemingly the right man for the job; not only has he worked on such legal series as “Eli Stone” and “The Practice”, but in a former life he was an attorney himself. He’s currently writing and executive-producing The CW’s superhero series “Arrow” – which, for the record, likely won’t have much to do with lawsuits or numbers.