– It all came down to RahRahBoom and Peter Pandemonium.

The “lady arm wrestlers” stood on opposite sides of the stage at a St. Louis dive bar.

On the one side: RahRahBoom, the “radioactive housewife,” wore a 1950s dress, green glitter lips and a scowl. On the other: Peter Pandemonium, a take on “the boy who wouldn’t grow up,” but, you know, it’s a woman who is deceptively good at arm-wrestling and known to chug tallboys between matches.

The contenders held grips built into a regulation arm-wrestling table and clasped palms. The housewife bent and licked her opponent’s hand.

“For good luck!” she said defensively as the crowd cheered.

A referee stepped in and warned her of the penalty box — in this case an actual cardboard box that can be put on an offender’s head. He blew the whistle to begin the final match of SLLAW XVI, the 16th bout in the history of the St. Louis Lady Arm Wrestlers.

For the uninitiated, SLLAW is a collection of women who, by day, work as clinical researchers, college professors and welders, but channel alter-egos in arm-wrestling tournaments about three nights a year to raise money for charity.

The arm-wrestling is real. Their over-the-top personas are definitely not.

The group is one of about 25 branches of the Collective of Lady Arm Wrestlers, which started in Charlottesville, Va., in 2008. Since its first bout in February 2014, the local group has raised more than $20,000 for small St. Louis charities.

But lady arm-wrestling here is about more than charity. It’s taking one of the most machismo-filled ways to settle a score and adding fishnets.

It’s campy characters commenting on the patriarchy as they flex their muscles and talk smack. It’s an esoteric tavern sport with rules and customs all its own. It’s a creative outlet. And it’s a novel way to spend a Saturday night.

“People ask if we train,” says founding SLLAW member Erin Fisher, aka the tap-dancing disgraced child star Surly Temple. “We’re like, ‘Yes, we work hard at picking up our beers.’ It’s not that serious.”

The group has embraced more structure since it started in 2014. Bouts that used to be unwieldy now have more choreography and preparation. They’ve done nautical, the circus, feminism and, once, a 16-wrestler “Royal Rumble.”

There’s also been a SLLAW calendar, a coloring book, and even a SLLAW fight, in which members wrestled in a kiddie tub full of coleslaw — SLLAW, get it? — to raise money for charity.

“It didn’t smell great,” Fisher says. “Yeah, we never did that again.”

Rules made to be broken

Ring girl Tammy Guns lazily walked across the bar stage to announce the start of a recent bout.

Ms. Guns, played by Washington University administrator Holly Schroeder, and described as a “south city tavern queen,” wore blue eye shadow and a cheetah print with a cigarette hanging from her mouth. She held her handwritten cardboard ring-girl sign, bordered in twinkle lights with an expression that said: “You happy now? May I please return to my bar stool?”

Every SLLAW event follows a traditional tournament style: four matchups, followed by two semifinals and a final. Best two out of three rounds wins each match. Feet must stay on the ground. No bent wrists. Each match is called if there is no pin after 15 seconds.

But it’s not exactly fair. SLLAW sells “bribes,” advantages or penalties. The crowd can pay to make a wrestler tire out her arm by holding a bedazzled Shake Weight, or summon a “brawl buddy,” another wrestler to add her hand to a side in the fight.

In the latest bout, confusion followed a good round of donations as Betsey Boss, Sugarplum Scary and Fiona Fangansniff’dher the Bisexual Shapeshifter all piled onto the stage for a mega-round, stacking hands on top of one another. It’s clear fan favorites have the advantage in SLLAW.

Master of ceremonies Lucky Slamrock, a leprechaun character played by redheaded Emily Kothe, responded to yells of “It’s rigged!”

“Uh, yeah,” she said into the mic.

“One side had two wrestlers. That’s what this is all about, strength plus shenanigans.”