‘Under the Dome’? Written by — and tweaked for TV by — Stephen King

When asked how he came to write the Season 2 premiere of “Under the Dome,” the television adaptation of his 2009 sci-fi novel that returns to CBS on June 30, Stephen King is refreshingly candid.

“I knew that George R.R. Martin had written a few episodes of ‘Game of Thrones,’ and I was very jealous,” said the prolific author, 66, via telephone from the North Carolina set of “Under the Dome.”

The series, which follows the inhabitants of the small town of Chester’s Mill, Maine, after it is suddenly cut off from the rest of the world by an invisible but impenetrable dome, became the most-watched new program on broadcast television last year, despite airing in what was once thought of as the dead zone of summer.

King, whose novels, novellas and short stories have been made into films and TV series dozens of times over the years with varying degrees of success (some, like “Carrie” and “The Shining,” have even spawned inspiring multiple adaptations), is not especially territorial when it comes to his work.

“It’s a no-lose situation,” he says. “If it’s good, I just say it was based on my work. If it’s bad, I just say, ‘Well, that wasn’t my idea.’”

Despite his laissez-faire attitude, King relished the opportunity to tinker with an adaptation of his own work. “It gave me a chance to set the arc in motion for the season,” he said between mouthfuls of pizza (served, much to his amusement, with a side of ranch dressing), “and it gave me a little more input into what was going to happen.”

“We thought this would be a great way to solidify the support of the fans but also put his creativity and imagination to work,” said show runner Neal Baer. “Stephen is very supportive and collaborative and has always said to us from the beginning, ‘It’s your baby.’”

While in its freshman outing, “Under the Dome” focused on the revelation of long-buried personal secrets, the season ahead will feature strong environmental themes, said Baer, as the residents of Chester’s Mill fight “pestilence and plague” resulting from their poor stewardship of the land.

“For me, the most interesting idea is this Malthusian concept that there’s too many people and too little space, there’s starting to be this talk about euthanasia and thinning of the herd, and that’s a scary idea,” said King, who will also make a cameo in the season premiere. “In a fantasy series, you have a chance to tackle some of these hot-button issues, and people will accept it, because it’s only make-believe.”

This foray into screenwriting is but the latest creative adventure for the intensely productive author, who will also release two books in 2014: “Mr. Mercedes,” a suspense novel published this month, and “Revival,” which is due out in November and which King describes as a “scary, dark piece of work” in a similar vein to “Pet Sematary.”

Given the sheer volume of writing he’s generated over the years — more than 50 novels, hundreds of short stories and a dozen or so screen- and teleplays — it’s not surprising to learn that King is a creature of habit, espeically when he’s home in Bangor, Maine, where he lives with his wife, Tabitha.

“Most writers have a ritual that would look strange from the outside,” he said, adding that he begins each morning with a three-mile walk “to open up my head and think a little bit,” followed by a pot of tea. After that, he settles down to write from about 8:30 a.m. until shortly after noon, with a goal of completing six pages a day. At this rate, working seven days a week, he can complete a draft of a novel in four to six months.

That’s not to say that King lives free of the self-doubt that afflicts most, if not all, writers. In fact, he’s currently a “mess” over the troublesome third act of an upcoming book.

“I don’t usually plot in advance, the book usually tells me what to do, but I’m getting to the point where there’s a lot of mist ahead and I just sort of hope things work out,” he said. “They usually do.”

King’s willingness to try out new forms extends to Twitter, which he joined in December. Unlike some other high-profile authors, King does not see the microblogging platform as the death knell of serious thought. Instead, he thinks of it as “the world’s biggest conversation,” though his social-media journey has not been without its setbacks.

In February, he was roundly criticized for a tweet suggesting that there was an “element of palpable bitchery” to Dylan Farrow’s New York Times op-ed piece recounting allegations of sexual abuse against her father, Woody Allen. (King quickly apologized for his word choice and begged for mercy from the Twitterverse.)

Mostly, King tends to stick to less controversial subjects on Twitter, using it like the rest of us — to talk about his favorite TV shows, which include “Orange Is the New Black,” “The Americans” and “Hannibal.” (Though even when he’s simply discussing TV, King can still get into trouble: See the outrage provoked in April when he tweeted about a major plot twist on “Game of Thrones.”)

King’s embrace of new technology is not all that surprising, given his status as an e-publishing pioneer: He released the books “Riding the Bullet” and “The Plant” online way back in the dark old days of 2000.

Last year, stirred to action by the 2012 massacre at Sandy Hook Elementary School in Newton, Conn., he released a lengthy essay, titled simply “Guns,” as a Kindle Single on Amazon, with proceeds going to the Brady Campaign to Prevent Gun Violence. He argued, at times vividly, that firearms manufacturers and advocacy groups like the NRA and not a so-called culture of violence, were responsible for the country’s mass shootings.

“Amazon is a little bit distressing that they seem to have taken over such a large share of the book market, but I don’t view them as the Great Satan,” he said.

And though he loves the convenience and readability of digitally published books, King still buys hard copies of all the e-books he reads. “I can’t entirely adapt to the idea of a purely electronic library,” he said. “When you only have it on a computer or a tablet, it seems ephemeral to me.”

As for his own writing, the author isn’t ready to rule out any particular genre or format. After all, he was wary of writing historical fiction until he penned “11/22/63,” about a man who travels back in time to thwart the assassination of President John F. Kennedy. But he says it’s unlikely he’ll churn out a “full-fledged memoir” any time soon.

“I’m not that interested in myself.”