Game Of Thrones: The Mad King has been lauded as a “titanic display of theatre magic” in near-universally positive reviews.

The play, which premiered at the Royal Shakespeare Theatre in Stratford-upon-Avon, is an adapted prequel of George RR Martin’s A Song Of Ice And Fire series.

Written by Duncan Macmillan, it is set 10 years before the events of the first novel, A Game Of Thrones, amidst a tournament at Harrenhal, as members of the Mad King Aerys II’s inner circle plot against him.

The Telegraph awarded the Royal Shakespeare Company production four out of five stars, calling it a “spellbinding spectacle” and wrote that the Game Of Thrones franchise has “yet another worthwhile and lucrative spin-off on its hands.”

WhatsOnStage called the play “a titanic display of theatre magic”, praising its “epic design” and the work of director Dominic Cook.

The publication also noted the story “ties up plot points from the Song of Ice and Fire franchise in ways likely to satisfy avid fans of the novels and the subsequent TV series”.

The Guardian gave the play four out of five stars, calling it an “action-packed saga” with “plenty of modern resonance”.

The reviewer speculated audiences may respond differently to the play depending on if they are already Game Of Thrones fans, writing: “This feels like a five-star production for most devoted throners but a three-star for those who haven’t seen the TV series.”

Another four-star review came from The Independent, which called the show “epic” with “shades of Shakespeare”.

The publication wrote that the play “has all the thrillingly staged battles, gory deaths and, yes, dragons that the most bloodthirsty fan could hope for. But there’s also a surprising amount of heart”.

A more lukewarm review came from The Times, which wrote that the play “seldom comes close to matching the grim aura of the TV series”.

The reviewer wrote: “Duncan Macmillan’s script is sorely lacking in poetry. Events plod forward, one after the other, and although Michael Shaeffer is a thoroughly compelling presence as the cruel and chronically unstable monarch Aerys, other performances seem nuance-free. Too many lines are simply shouted. You expect better of the RSC.”

Game Of Thrones: The Mad King runs at the RSC until September 5.