The apocalypse is coming. Supernatural creatures have crept into our world to destroy everything. The problem is that only you can see them, which means only you can stop them. Why? You’re not entirely sure — if only you didn’t suffer from that pesky amnesia. But what you do know is that you’re a Saint now, and that gives you the power to, just maybe, stop the end of the world.

That’s the premise for the Apocrypha Adventure Card Game, the spiritual successor to the Pathfinder Adventure Card Game. The ambitious horror-themed card game by Mike Selinker and Lone Shark Games made its debut at Gen Con in Indianapolis and was one of the biggest surprises at the show this year due its most unique feature: It’s playable as either a traditional cooperative card game or as a tabletop role-playing game.

For those familiar with the Pathfinder ACG, there are some immediate similarities in Apocrypha’s mechanics. One to six players will each embody a unique character, referred to as Saints, set in our modern world. The diverse cast ranges from an unlicensed physician who dresses like a witchdoctor, to a John Rambo-style tough guy and the World’s Luckiest Grandma. Each player will have a deck of cards that, over the game’s sprawling campaign, will evolve as more powerful and beneficial cards become available.

Each scenario has its own unique objective, though many boil down to discovering and defeating some form of mastermind before the game’s Doomsday Clock expires. Saints will investigate various locations, such as a dive bar, a school or a mall, encountering enemies to battle and friends to acquire along the way. Resolution of encounters happens via dice, where players build up a fistful based on which virtue (Soul, Mind, Body, and Rage) is called upon for any given challenge. It’s a simple system which strongly encourages teamwork, as most monsters may be too tough for a single Saint to tackle alone.

Apocrypha uses fanciful terminology for most of its simple mechanics, which was slightly confusing on my first playthrough. Thankfully, the game includes a clearly labeled pack of cards that functions as a self-contained tutorial. One of the cards even features a QR code directing smartphones to a tutorial video that further explains Apocrypha’s mechanics and terminology. Once we understood how everything connected together, my team fought our way through hordes of teenage werebears saved the day.

Each of Apocrypha’s missions lasts about one to two hours. Over the course of the 20-scenario campaign, players will have opportunities to fine tune their decks with upgraded cards to combat the apocalypse. Fleeting and permanent upgrades that enhance your character will unlock at various stages as well, giving a tangible sense of RPG-like progression for your chosen Saint.

Apocrypha owes much to its Pathfinder predecessor, while taking the opportunity to clean up some of the original game’s shortcomings. But according to Selinker, the horror-fueled world of the Saints was what he envisioned for the system when it was first conceived.

“I came up with the idea of this location-based, run-around game and came up with a pretty solid system, but knew full well that it wouldn't work in play testing if it wasn't about something,” Selinker told Polygon in an interview on the convention floor. “We had this setting, but very quickly we knew that we wanted it to be a fantasy game out of the gate and there was only one company we went to for that, and that was Paizo.”

Lone Shark Games went to work on adapting Pathfinder’s original adventure, Rise of the Runelords, into this new card game system. They expected fans of the tabletop RPG to enjoy it, but they didn’t anticipate the reaction it received when it debuted at Gen Con 2013. Pathfinder Adventure Card Game: Rise of the Runelords sold out within the first hour of the convention. Its success spawned multiple sequels, all based on existing Pathfinder stories like Skull & Shackles and Mummy’s Mask.

According to Selinker, the success of the Pathfinder Adventure Card Game is what granted his team the stability and independence to finally create the game they originally envisioned. It successfully raised more than $300,000 during its Kickstarter back in April 2015.

But despite the game utilizing many shared RPG elements with Pathfinder, Selinker wanted to take the actual roleplaying aspects to another level — by actually creating Apocrypha to be playable as a card-driven tabletop RPG, complete with a game master role called the Guide.

“It's exactly the RPG I wanted it to be, when it runs like a card game,” said Selinker. “And that doesn't sound like a positive for a RPG because we think, 'Oh my god, the things you want are Game Master agency and sweeping storytelling.' But in this case, it just runs for you. And what you do is provide the creativity and reaction of the Game Master, and so now anyone can be one. And that was what's missing from a lot of RPGs is, we're going to let the game run for you.”

I needed to experience it for myself to wrap my head around the concept, so I ran a table of Apocrypha in RPG mode for Gen Con attendees. After some initial fumbling, my players eventually began to immerse themselves in the story we were telling together. They explored locations and followed leads they wanted, meeting non-player characters to interact with and fighting monsters, while letting the cards handle the actual resolution of encounters. It left me feeling excited about the possibility of running further scenarios as a RPG, while also feeling reassured that a campaign could seamlessly switch over to the traditional mode at any time.

Selinker’s goal for the RPG mode is to provide a less intimidating way for potential game masters to learn that skill.

“I'm trying to enable you to feel good without feeling like the burden is just overwhelming for you as a game master or as a narrator, both of which are incredibly difficult. The Dungeons & Dragons style, which obviously I love, is incredibly difficult to do. It's an A-level skill. Similarly, running Fiasco and other storytelling games like that can be incredibly intimidating. And so without a supply of game masters, RPGs don't exist. And so my games are like, ‘I got you, don't worry, you'll be fine.’ And I think we really nailed it here.”

The game includes a story book which contains pages of flavor text for each individual scenario for both Guides to flesh out the world, and for traditional card game players seeking deeper immersion. Additionally, a companion iOS and Android app for Apocrypha also launched, granting random daily modifiers for those seeking a greater challenge, while also allowing players to track the progress of their Saints over the course of their campaign.

Apocrypha Adventure Card Game is widely available now for $74.99. The app is also available on Amazon.

Correction: An earlier version of this article misstated the lycanthropic condition of the teenagers in Candlepoint. The teenagers in question were werebears, not werewolves. Polygon regrets the error.

Polygon was on the floor at the 50th annual Gen Con tabletop gaming convention in Indianapolis, Indiana. You can find all our stories here as they go live throughout this week.