The cable network HBO has signed the stars of Game of Thrones to a new deal which secures their services through to a potential seventh season of the show.
The show is currently filming its fifth season, which is due to debut in 2015.
The new deal also pushes a handful of the show's lead actors onto the top salary rung of TV acting talent in Hollywood, earning roughly $US300,000 per episode.
Details of the new salary deal were revealed by the industry trade newspaper, The Hollywood Reporter.
The deal is unusual in that it effectively splits the actors into three tiers.
Game of Thrones has an unusually large cast: 30 actors appeared in three or more episodes of the show's fourth season.
Most actors in US television are signed to six year contracts.
In exchange for extending the contract for a potential seventh season, HBO has given the cast early pay increases for the upcoming fifth and subsequent seasons.
The so-called "A tier" includes Lena Headey (Cersei Lannister), Peter Dinklage (Tyrion Lannister), Kit Harington (Jon Snow), Nikolaj Coster-Waldau (Jaime Lannister) and Emilia Clarke (Daenerys Targaryen).
The "B tier" includes Maisie Williams (Arya Stark), Sophie Turner (Sansa Stark) and Natalie Dormer (Margaery Tyrell).
The pay increases are tied to the tier into which an actor falls.
Game of Thrones is one of HBO's most valuable properties and the push to stretch a seventh year into the cast's contracts reflects the long-term value the premium cable operation places on the show.
The series commands a weekly audience of more than seven million viewers in the US, and has been sold extensively around the world. Unusually, and valuably, it has increased its audience every season since its debut in 2011.
HBO confirmed in April it had commissioned a fifth and sixth season.
A seventh season, though now covered by the actors new contracts, has not yet been commissioned by the network, but seems likely.
The new contracts, however, do not guarantee that the actors who have signed them will live to see a seventh season.
Game of Thrones is notorious for killing off its main characters.
More than 20 characters have been killed off in the series since it launched.