may be a cultural phenomenon now, but the producers of the hit HBO show say it wasn't looking that way early on.
Showrunners David Benioff and DB Weiss have revealed just how bad their first TV pilot for the show was.
"Watching them watch that original pilot was one of the most painful experiences of my life," Weiss said.
"As soon as it finished, [Mazin, one of the podcasters] said, 'You guys have a massive problem'."
Benioff said that line - "massive problem" - was all he could think about after the screening.
Mazin told him to "change everything".
"I was taking notes, and I had this yellow legal pad, and I just remembered writing in all caps, 'MASSIVE PROBLEM,' and it's all I could think about the rest of the night."
The pair reshot 92 per cent of the pilot, switched out actors and changed directors, resulting in the show that will soon air its sixth season.
As Mazin says: "That is the biggest rescue in Hollywood history ... you turned it into something brilliant."
sixth season begins on Sky TV's SoHo channel from April 24.
Watch the trailers for the season below: