The Flash is an American television series developed by writer/producers Greg Berlanti, Andrew Kreisberg and Geoff Johns, airing on The CW. It is based on the DC Comics character Barry Allen / Flash, a costumed superhero crime-fighter with the power to move at superhuman speeds, who was created by Robert Kanigher, John Broome and Carmine Infantino. It is a spin-off from Arrow, existing in the same fictional universe. The series premiered in North America on October 7, 2014, where the pilot became the most watched telecast for The CW. Primarily filmed in Vancouver, British Columbia, Canada, the series follows Allen, portrayed by Grant Gustin, a crime scene investigator who is struck by lightning during an explosion of the local particle accelerator and gains super-human speed. Barry, teamed with scientists at S.T.A.R. Labs and under the alias of the "Flash", uses his new powers to fight crime and help stop meta-humans that also gained powers, but instead chose to use them to commit crimes.
Initially envisioned starting as a backdoor pilot on Arrow, the positive reception Gustin received during his two appearances as Barry on Arrow before he acquired powers, the executives chose to develop a full pilot to make use of a larger budget and help flesh out Barry's world in more detail. Colleen Atwood, costume designer for Arrow, was brought in to design the Flash's suit, which was modeled after the comic books. The creative team wanted to make sure that the Flash would resemble his comic book counterpart, and not simply be a poor imitation.
The Flash has received generally positive reviews from critics, and its premiere episode became the most watched premiere since The Vampire Diaries in 2009, and the second-most watched premiere in the history of The CW. The series won the People's Choice Award for "Favorite New TV Drama" in 2014. On January 11, 2015, The CW renewed The Flash for a second season.