Game of Thrones spinoffs: George R.R. Martin reveals new details

HBO's Game of Thrones in its home stretch. But the game isn't over for its creator, George R.R. Martin, who is in the thick of planning as many as five new Game of Thrones-related series for the network.

Posting on his website, Martin specified that each concept under development is for a prequel, not a sequel. He indicated any of the new series would be populated with fresh characters.

He noted that it remains to be seen how many of the pilot scripts currently being written will actually be filmed, and how many series might result from those filmed pilots. He says he is working with all the writers.

While Martin didn't reveal reveal what the new spinoffs would be about, he did say what they wouldn't be about.

"None of these new shows will be 'spinning off' from GOT in the traditional sense. We are not talking Joey or AfterMASH or even Frasier or Lou Grant, where characters from one show continue on to another. So all of you who were hoping for the further adventures of Hot Pie are doomed to disappointment."

Still working on sixth book

And Martin took the opportunity to reassure his readers that he's still working on Winds of Winter.

That's the long-awaited sixth book in his series A Song of Ice and Fire, which started with A Game of Thrones. 

"I will confess, I do wish I could clone myself, or find a way to squeeze more hours into the day, or a way to go without sleep," he said.

Just 13 episodes remain for Game of Thrones, which HBO is splitting into two final seasons. It returns in July. It's been HBO's highest rated and most-watched show ever.