Stars of “Girls Guts Glory,” a Dungeons & Dragons Web series, from left: Kimberly Hidalgo, Erika Fermina, Kelen Coleman (kneeling), Rachel Seeley, Allie Gonino, Alice Greczyn, Sujata Day and Kelly Lynne D’Angelo. Early episodes were met with harsh comments: “Like. . . ‘There’s no way they actually play. No one plays D&D who looks like that,’” Fermina recalls. (Chris Koeppen)

BURBANK, Calif. — There was something about Dungeons & Dragons that spoke to Mario Alvarenga in a deep way. He tried it for the first time five years ago — never mind that he was not a teen, as most newbies are, but an adult. While experiencing the role-playing game, he could imagine scenes down to the tiniest detail: the bump of cobblestones on a street, the smell of baked goods in a market, the coldness of the wind. The boredom in his life melted away.

He joined one regular group, then two, then four. Soon, he was leading games as a Dungeon Master at his local game store. Alvarenga, who is 31 and works full time as a caregiver, quickly found his entire nonworking life overtaken by elves, gnomes, dwarves and wizards.

“If you asked me to add up how many hours I spend thinking about Dungeons & Dragons, I’d be too embarrassed to answer,” he says. His only regret? That he didn’t start playing sooner.

Yes, D&D is back. But it’s cool now (sort of). And legions are into it, including an unprecedented number of adult and female players, attracted by a popular recent revamp and new online playing options. It’s the ultimate sign that nerd culture is now mainstream.

Vin Diesel, Jon Favreau, Drew Barrymore, Dwayne Johnson, James Franco, Stephen Colbert, Anderson Cooper, Ta-Nehisi Coates: The list of celebrities who have “come out” about rolling the 20-sided dice is as long as a wizard’s beard. “Game of Thrones” writer George R.R. Martin first flexed his storytelling muscles as a young Dungeon Master, as did the showrunners on the HBO series. Joe Manganiello is so obsessed that he wrote a D&D movie script. The game has been on TV shows including “Big Bang Theory” and “Futurama.” Next month will see the release of a “Stranger Things” tie-in D&D starter set.

The game’s popularity has waxed and waned over its 45-year history. But in 2018, its developers, Wizards of the Coast, sold more units than ever before.

“If you told me that a game that has a 328-page rule book would have grown to the size it’s grown in the past five years, I wouldn’t have believed it,” says Mike Mearls, the game’s lead developer. “How in the world of computers and video and mobile games does this stand out?”

Essentially, D&D is collaborative storytelling. Players pretend to be fantasy characters who embark on a group adventure. They battle monsters, explore terrain and roll the dice to decide outcomes. A Dungeon Master guides the narrative.

D&D has come a long way since Gary Gygax and Dave Arneson invented it in 1974 as an alternative to miniature-military war gaming. No longer is it a game to hide out with in Mom’s basement.

Today, people play it at bar and restaurant pop-up events such as “Drinks and Dragons” in Philadelphia, and “Orcs! Orcs! Orcs!” in Portland, Ore. They pay $2,650 per person plus lodging over four nights to play it in Caverswall Castle in Staffordshire, England. They swell the ranks of the D&D Meetup groups from Tokyo (37 members) to Kolkata, India (501 members).

During the “Satanic Panic” of the 1980s, D&D got a bad rap. Religious groups who associated it with the occult and devil worship feared the game’s power over impressionable young minds. When two teenagers, both avid players, committed suicide, they launched a campaign against it.

Today, however, the warhammer has swung the opposite way: D&D is considered wholesome, therapeutic.

While parents of one of those teens sued a school principal in 1983 for allowing her son to play, teachers now organize students into D&D after-school groups and summer camps. Some therapists use D&D to teach autistic kids social skills. And when a UCLA researcher adapted the game for a third-grade class, the students improved in areas including math, reading comprehension and conflict management.

Casting about for something he and his 11-year-old son, Gustavo, might do together for fun, automotive product developer Jeff Moss, 50, suggested D&D, his old junior-high hobby.

Within days, Gustavo was quoting verbatim from the rule books. Within weeks, he and Dad were logging six hours every Saturday at a D&D table at Boyle Heights Arts Conservatory in Los Angeles.

“The Dungeon Master’s describing the final blow to get rid of a monster or whatever. And I’m looking at this kid’s face and it’s just lighting up,” Moss recalls. “There’s no computer screen, but he’s visualizing everything going on. I thought, this is amazing. So I made it a priority for him to play.”

As Moss puts it: “Nerd culture was not cool back in 1982. You’d get beat up for it. Now, everybody knows that the nerds are the ones that hire you.”

More people are playing, partly, because it has never been easier. D&D used to be a nitpicky, number-crunchy affair. Then, in 2014, Wizards of the Coast released a new edition — the beloved 5th edition — that is more streamlined, more spontaneous and less rule-driven. As the longtime L.A.-based player Barry Thomas Drake, 58, explains: “No more arguing about the precise number of mouse hairs you need for a certain spell.”

The company also made it more inclusive. Gone is the rule mandating female characters’ strength be less than males’. Gone is the sexist artwork — no more armored bikinis, no more monsters with breasts, no more topless ladies (unless her character really, really calls for it).

Characters come in a rainbow of skin colors and body types and sexual orientations — like the wood elves who identify as non-binary.

“You could,” the “Players Handbook” suggests, “play a female character who presents herself as a man, a man who feels trapped in a female body, or a bearded female dwarf who hates being mistaken for a male.”

Women, in particular, love the new edition. D&D was originally a nerdy guy thing, emphasis on guy. Yet the number of female players is at 38 percent and climbing, according to Wizards of the Coast.

Their involvement is driven by Web series such as “Girls, Guts, Glory.” Conceived by eight young L.A. actresses, it started as a way for them to hone their improv skills and get together for “scheduled bonding time.” None had much prior experience with D&D, and early episodes were met with cynicism.

“There were rude comments,” says one of them, Kim Hidalgo.

“Like, ‘Oh, they’re just models that Wizards of the Coast hired,’ ” Erika Fermina says. “Or, ‘There’s no way they actually play. No one plays D&D who looks like that.’ Someone compared us to the Monkees. A manufactured group.”

“A girl band,” Alice Greczyn says.

The trolling has since been replaced by devotion. One mom in coastal Georgia confesses that not a slumber party goes by when her 12-year-old and her friends don’t tune in.

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These days, even the most surreal of feats is possible: playing D&D as a career. Popular podcasts such as “The Adventure Zone” and “Critical Role” have turned anonymous players into Internet royalty. “Critical Role” began as a group of professional voice actors in Los Angeles goofing around with D&D in one another’s living rooms. It’s become a multiplatform series with an audience of half a million people a week.

Satine Phoenix started Los Angeles’s largest D&D Meetup group. She’s now Wizards of the Coast’s official community manager for the 40 million people who play the game worldwide. She travels the globe spreading the D&D gospel, organizing charity events, hosting Web series, fielding “social navigation” questions from Dungeon Masters and generally “orchestrating all of the experiences.”

Phoenix, who has played since age 8, cites D&D as her “longest relationship.”

“It’s a dream come true. And I didn’t even know I had this dream. Didn’t know it was an option,” she says.

Technology has been a game changer. In 2019, people play D&D by video conference, via Skype and Discord. They use dice-rolling apps, fill out online character sheets and draw maps on laptops and iPads instead of on graph paper. They live-stream on Twitch. When they can’t make it to a physical tabletop, they log on to “virtual tabletops” such as Fantasy Grounds and Roll20 to crawl through dungeons with players half a world away. Here, Dungeon Masters hire themselves out like itinerant knights — they’ll lead your campaign for $10 to $20 a head.

“Gone is the era of ‘I can’t find a group,’ ” Phoenix says. “Now, it’s ‘what style of game do I want?’ ”

But still, as in 1974, all you really need for a good game of D&D are paper, pencil and dice.

“When you’re at a table, no matter what age you are, it’s invigorating,” Phoenix says. “Even if it’s just for those couple of hours, you feel . . . you feel.”

On a balmy Saturday night, a dozen people are sitting around a D&D table at Boyle Heights Arts Conservatory. Frank Contreras, 18, who typically plays two back-to-back sessions here every weekend, says he likes the “possibilities” D&D stories offer. “Our world, the real world,” he adds, “is kind of dark.” He’d just finished decapitating an ogre.

With D&D, a quiet, gray-haired accountant on disability like Leigh-Anne Anderson might reinvent herself as a sexy barbarian criminal enforcer suffused with rage. Anderson, 50, plays in Contreras’s evening group.

“I have a picture,” she says, unfolding a drawing of a buxom woman with long, flowing red braids. “That’s me.”

For their Dungeon Master, Mike Arellano, it’s less about escaping the real world than building an alternate version of this one. Arellano maintains a home library of more than 1,000 D&D-related books — on the history of China, Africa, Egypt, on coinage and trade and castles. “Because you never know when you might need to describe the proper layout of a burial vault.”

For pretty much everyone, the game is about connection. Across town at Mario Alvarenga’s table at Burbank’s Geeky Teas, analytical chemist Kristi Halbig, 40, admits that playing D&D forces her to “talk to real human beings.” She’s painfully shy and could otherwise spend her entire day staring at a computer.

Sitting next to her, 17-year-old Jacob Whaley concurs: “My dad says, ‘I don’t understand what it is. But I’m happy you’re hanging out with people.’ ”

Correction: This story originally stated that the Caverswall Castle D&D vacation is over a weekend. It actually is four nights, mid-week. The story also has been clarified to state that the trip requires lodging costs in addition to the registration fee.

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