Uncovering and explaining how our digital world is changing — and changing us.

At first blush, Tuesday night at Folsom Street Foundry may look like just an unusually busy weeknight at a San Francisco bar. The music is loud, the drinks are flowing, and the chatter among the various 20- and 30-somethings is nonstop.

However, the music is not your typical bar fare of top 40 hits and FM radio flashbacks — it’s all bleep-bloopy samples and remixes of ’80s videogame music. And that chatter is not centered around tables of drinks — it’s taking place below, beside and around a series of screens and televisions.

Every Tuesday for the past month, Folsom Street Foundry has been overtaken by hordes of videogame fans, some of whom come to watch, but most of whom come to play.

There’s a custom arcade game emulator, offering hundreds of games from Frogger to Wheel of Fortune. Want to play Halo? Sit on the couch, grab a controller and look up — it’s being projected on the wall. Or maybe you’d prefer Mario Kart, or Dota 2, or Street Fighter. Up above, projected onto the wall next to Halo, you can watch live broadcasts of Hearthstone, League of Legends and even Twitch Plays Pokémon. In the back, you’ll find every entry in Nintendo’s fighting game franchise Super Smash Bros., including an unofficial hack of the game, Project M, designed specifically for competitive play.

If you’re more of an old-school type, central tables also offer card games, board games, dice games, ping-pong and beer pong. Just be careful not to overshoot the ping-pong table (as I did about 10 times, consecutively, last Tuesday) or you might find yourself chasing the ball through a crowd that’s trying to watch a Bubble Bobble duel.

The weekly events here are organized not by the bar, but by an outside team of nine that calls itself Showdown eSports. Co-founder C.J. Scaduto said the gaming nights are a “proof of concept” that games can attract a healthy nightlife crowd.

“This is a test of, are gamers willing to come out to a bar to do fun things that aren’t available elsewhere?” Scaduto said. “People like to dance, they go to a dance club. This is more like a geek’s paradise.”

Over the past four weeks (tonight will be SF Game Night number five), Showdown has begun to figure out what games people want to play, and where to put them. Its main limitation: Hardware, most of which the organizers bring and set up each week from their own collections.

However, attendees can and do bring their own gear as well. Early in the evening, only one game of Super Smash Bros. had started in the back, but an onlooker stopped me when he noticed I had a backpack on.

“You don’t have a GameCube or Wii on you, do you?” he asked. “We only have one.”

Within an hour, two more Wiis and a Nintendo 64 had materialized, and the Smash Bros. corner — one of the gaming night’s most heavily trafficked — was sated.

“Oh, brutal!” a gawker around the N64 yelled after a surprising defeat.

“The fuck?” the loser eloquently replied.

It’s a different vibe from professional competitive gaming, or eSports, where some companies borrow credibility by aping traditional sports culture. By contrast, the SF Game Night crowd plays less like “cyber-athletes” and more like friends in a really, really big living room. Some attendees offered up their controllers in case viewers wanted to tag in, while others actively sought out fresh blood.

“Anybody want to play beer pong?” one player said to no one in particular, at around 7:30 pm. “We need one more.”

Despite this easygoing atmosphere, Scaduto said professionalizing the game nights — at least a bit — may turn Showdown eSports into a business rather than a hobby.

Currently, the group borrows Folsom Street Foundry’s space for free and gets a small percentage of the bar’s food and drink sales each Tuesday night. But the “vision,” as fellow co-founder Cal Leingang put it, is to run bona fide gaming tournaments, complete with entrance fees and prizes, that could then be broadcast online on a game-streaming site like Twitch to further spread the profile of the bar-gaming scene.

In addition to the money, Showdown also wants to host its own tournaments to ensure that there will be something worth seeing during its attendees’ waking hours.

“An eSports tournament in Poland is 6 to 8:30 am for us,” Scaduto said. “No gamer’s going to come out for that. Some of them are still going to sleep!”