The website for the game Cordial Minuet is nothing if not unsettling. The first thing you see when you open it is a pentagram followed by a series of spells: for making a husband faithful, traveling twenty miles an hour and for "winning a fortune in games where numbers are foretold." The rest of the page is littered with rants that sound like they've been ripped from the label of a Dr. Bronner soap bottle or the rantings of an internet conspiracy theorist:

Have you ever wanted all of the POWER with none of the RESPONSIBILITY? … Many people, in fact most people, are still waiting for the HARPOON OF TIME to spear the WHALE OF TRUTH. The fact that you are READING THESE WORDS means you may suspect that this strike is NEVER GOING TO HAPPEN. Unlike the UNWASHED MASSES, you might have always felt like SOMETHING WAS GOING ON. Is it possible to wake up each morning, look in the mirror, and announce with conviction that TODAY IS THE DAY, and most importantly, BE RIGHT? There is only ONE WAY to find out.

And then comes its most tantalizing promise: that "the ancient dreams of the internet have mostly been squandered by fools and charlatans, but there is one dream left alive," the text on the web reads. "Gold." Elsewhere, a bright orange hyperlink awaits with the words, "THE DOOR IS OPEN."

At first, it's hard to know what to make of any it, which according to the game's creator, Jason Rohrer, is kind of the point. "It looks really sketchy on purpose; it's meant to feel like you're stumbling your way into this underground society. And then it asks for your credit card number." You'll need that, of course, for the gambling.

Rohrer has a long history of making unusual games, including the endlessly recursive shooter Inside a Star-Filled Sky, and the simplistic but touching Passage, which simulates a lifespan in five minutes. When his "holy object" game, Chain World, was accidentally appropriated by "social entrepreneurs," he let it all unfold. His most recent (and most controversial) game is The Castle Doctrine, which he describes as "a massively multiplayer game about the social construction of manhood and home invasion and self defense."

But Cordial Minuet—the name is an anagram for Demonic Ritual, of course— is something different and stranger still: a mathematically inspired gambling game based on historical occult summoning rituals that asks players to bet real money on their credit cards. And soon, twelve players will receive mysterious amulets of actual gold, silver and bronze, painstakingly hand-crafted by Rohrer himself.

Each one is inscribed with a sigil that represents a particular demon, as well as further clues that may unlock what Rohrer claims is "the door to endless riches." It's hard to tell how serious he is—or what that really means—but of course, that's all part of the game.

Although Rohrer had a youthful interest in the occult, Cordial Minuet was originally inspired not by black magic but by gambling. "I started studying games throughout history that have been played for money, and one book on the history of gambling talked about how a lot of these games were originally religious. How the temple doubled as a casino on the off nights, or how rolling the bones was for communing with the gods."

That's when the idea came together: why not make an occult game that asked people to put real money on the line, a phenomenon that didn't seem so different to him from the ritualistic way so many people already approach gambling. "One of my friends talks about how a modern casino is a cathedral where we get to sacrifice a bit of money on the altar of the gods of chaos," says Rohrer. "We want to laugh in the face of the things that control our lives by throwing a little money down on the roulette wheel."

The structure of the game took shape when he discovered the magic square, a grid of numbers where the digits of every column and row always add up to the same number. It was not only a fascinating mathematical object, but a tool historically used for summoning and magical rituals. It was often used to create sigils for demons by converting the letters of their name into numbers based on their position in the alphabet, and then drawing a line between them on the grid. The resulting pattern was thought to represent the demon's true name, and command power over them.

"If you wanted to summon the demon, you might carve that into something or stare at that sigil while reading an incantation," says Rohrer.

Although the language on the website is deliberately absurd—a mashup of both the hucksters of old and modern digital charlatans—there's far more than parody going on beneath the surface of its occult trappings. Rohrer says that the images and symbols were chosen very deliberately, after extensive research that included digging into a 16th century book on European black magic.

"It's not just skin-deep," says Rohrer. "Even the mechanics of the game itself are based around actual summoning rituals. As you're picking rows and column and charting out these six specially selected squares with the other person, you're actually composing a sigil as you do that." He pauses for a moment and laughs. "If you notice the lights flickering after a round, maybe Azeroth is standing right behind you."

The game itself is simple enough: You're presented with a magic square numbered one through 36. You receive two pointers adorned with Hebrew letters, and asked to select two columns each round: one for yourself and one for the other player. Your opponent does the same with rows. When they intersect, you add the numbers from those squares to your score. Between each round, you make bets that feel a bit reminiscent of poker; numerous strategy discussions in the forums compare the game to Texas Hold Em.

Despite being inspired by games of fortune-telling and chance, Cordial Minuet isn't a game of chance at all. Indeed, if it were, it would probably be illegal. Rohrer says the rules regarding online gambling revolve around whether or not it's a test of skill or luck. He's designed Cordial Minuet to circumvent these laws by removing elements of random chance, anything functionally works as a roll of the dice.

"In common parlance, it is a gambling game because are placing bets," says Rohrer. "But it's not an illegal gambling game. That's the important distinction." The stakes can be rather low for the curious; all you need to do is ante up two dollars, and you're in.

But others play for much higher stakes. When a dot com millionaire started playing Cordial Minuet, Rohrer says the man got bored at gambling for peanuts, and started proposing more and more expensive games to make things more interesting. "He kept losing, on purpose at first, to lure the bigger players of the game into higher and higher stakes," says Rohrer.

But even after the millionaire started playing to win again, he ended up losing anyway. Eventually he started a game with a thousand dollar stake, the highest yet, and soon another player had cleaned him out to the tune of $6,000. Oddly, says Rohrer, the winner never claimed his money. "Every once in a while he'll propose a $6,666 game to see if anyone will call him on it." To date, no one has.

Although the game has occasionally been referred to as "satanic," Rohrer insists that there is no link to the Lord of Darkness. "It's not satanic!" he says, frustrated. "I researched the occult, black magic, and demonic rituals, but Satan wasn't part of any of that. 'Satanic' is this blanket cultural label that gets applied to anything occult and weird by the Christian majority."

He admits that the imagery might scare some people off, especially when paired with a request for financial information. "But it's a game that looks really sketchy on purpose; it's meant to feel like you're stumbling your way into this underground society as you're stumbling through this website," says Rohrer. Half the fun is winding your way into the weirdness, and trying to decipher the symbols and promises of riches that circumscribe the mathematical poker ritual.

I've already given the game my credit card number, and Rohrer reassures me that it's safe. Before releasing the game, he offered a $3,000 bounty on a hacking website to see if anyone could get in, but no one claimed the money. He also notes that credit card numbers aren't stored on his server; after they're approved by his credit card processor via a secure connection, they disappear. Although he's been working on Cordial Minuet for a year, only two months were spent on making the game itself, and the rest on making sure its infrastructure was secure.

Despite the legal and security complications, making a game that involved real money was the heart of the experience Rohrer wanted people to have with Cordial Minuet. "I like games that reach out into the real world in one way or another," he says. "When I played poker, I found that the experience was so much more emotionally rich and evocative when I was playing for real money. These points have meaning outside the game. You can withdraw them and use them to buy food… Some people talk about how they feel so emotional even when they lose just a penny, how much money is magnified in this game in terms of its importance."

But the greatest excitement in the game is currently not for cash but for the secret amulets, which will be assigned to winners with the help of mysterious cabal. Each winner will receive a real gold, silver or bronze medallion, inscribed with a different symbol. While the community around the game has already deciphered what the symbols signify—or more specifically, which demon they represent—no one knows what lies on the reverse side of each amulet. That's a secret that only the winners will be able to discover, and what they do with that information is is up to them.

Will they share it with the larger community and try to solve the puzzle together, or hoard the information for themselves? "If you have part of a secret, what do you do with it?" asks Rohrer. "Do you share it with everybody else who has a part it? Or do you try and hold it back and get their secret first?" If a winner refuses to crowdsource their knowledge, they will essentially create a lost amulet—and a missing piece of the puzzle that might prevent any of them from unlocking that "door to endless riches."

Making the amulets from scratch was no simple feat for Rohrer; he constructed them using a technique called lost wax casting, which involves carving the object out of wax, embedding it in plaster, burning out the wax in a kiln, heating the precious metals in a centrifuge before adding them to the hold, plunging it into water, and then scrubbing them smooth with polishing wheels. "They almost have mirror shines on them," he says proudly.

Still, they haven't gotten quite the reception he was hoping for. The demonic treasure hunt was inspired by a successful contest he held for his last game called Steal Real Money. "It got picked up and covered from coast to coast all week long on every website, even mainstream websites," says Rohrer. "But this contest where I'm actually giving away real gold? Nobody's writing about it. The people who are into the game are really really into the idea of these amulets and are playing like crazy trying to win them. But it didn't do much to attract anyone who's not into the game already." He sighs.

Despite the small size of the Cordial Minuet community, Rohrer loves that the people who are into the game are really into the game, researching and dissecting every clue with the ardor of a Game of Thrones fan. They've noticed, for example, that while there are twelve amulets, one of them is numbered thirteen instead of eleven, and that this particular amulet happens to have thirteen notches on it. What does it mean?

In the meantime, Rohrer is heading to Las Vegas to try and work his way into the world of high stakes professional poker, where he hopes to connect with people who might be interested in playing the game for much larger sums of money and make it more profitable.

"I'm always trying to do something new and crazy and different, but most of the time there's a very small percentage of people who appreciate those weird, different things," he says.