⚡ Worldbuilding on the Digital Frontier

How crypto and sci-fi inspire next-generation game design

I've read the book Ender's Game at least ten times in the last ten years. There are so many wonderful things about the series, but what I really latched on to—and predated the work I'm currently doing—was the part where Ender's siblings wrote articles on web forums with fake names. I was and am still obsessed with the idea that relatively powerless figures can leverage online information ecosystems to make shit happen on a geopolitical scale.

I think a lot of technologists have something similar to my Ender's Game moment. They come across a creative work—a book, a video game, a movie—that shocks them into imagining the wild utopias and dystopias that technology makes possible.

Today, I'm sharing an interview with my good friend bgu.1 He's a 2020 Thiel Fellow currently building the Dark Forest video game and other zero-knowledge cryptography experiments. Inspired by our last event with Cory Doctorow, I hit him up to chat about his sci-fi inspirations and the design challenges around Dark Forest. Bgu also helped create HackLodge, a program for student developers, and he spends his time thinking about crypto, communities, and digital worlds.

🗺 Worldbuilding on the Digital Frontier

This interview has been edited for length and clarity.

What was the first sci-fi book you read that really changed the way you approach your work?

The seeds of my interest in decentralized technology were planted about five years ago, when a friend gave me a copy of True Names: and the Opening of the Cyberspace Frontier. It contains the novella True Names by Vernor Vinge and a collection of essays from cypherpunks and other thought leaders in early cryptography.

Vernor Vinge was one of the first authors to hypothesize about a digitally interconnected world many years before the early internet. True Names lays out a vision for pseudonymity and anonymity in cyberspace; for example, the idea that because of privacy-preserving cryptography, cyberspace may be much harder for traditional meatspace authorities to exert control over. Like other influential sci-fi books like Snow Crash and Ready Player One, the most powerful people in True Names are totally unassuming in the context of traditional power structures—but wield enormous power in a digital reality. Vinge inspired a lot of writers and technologists to start actually building towards this vision.

So tell me about what you're working on now!

For the last 18 months, I've been working on a project called Dark Forest. It's a massively multiplayer, real-time strategy game built on the Ethereum blockchain. It uses new cryptographic technology to make much richer and more dynamic online worlds than were previously possible.

Around 2019, there was an explosion in a subtopic of crypto called zero-knowledge cryptography (ZK crypto), which allows you to perform verifiable computations without showing what data you're performing the computation on.2

Right now, there are two applications of ZK crypto that people care a lot about. One is privacy tech, like sending anonymous cash back and forth on the blockchain. The second is scalability tech: there are ways to use the mathematical techniques behind ZK crypto to make blockchains more efficient. But the third application that I'm most interested in—and that there's been very little activity on so far—is using ZK crypto to create games and digital worlds.

Can you explain me how ZK crypto works in the Dark Forest game?

All games can be divided into two categories: complete information games and incomplete information games. Complete information games are games where everybody knows everything going on, like checkers or chess. Incomplete information games are games like poker or Starcraft where not everybody has full data on the world state. For example, I don't know what's in your hand in poker, and you don't know where my base is located in classical strategy games.

This distinction matters because incomplete information games often have a much richer and deeper strategy space and more interesting social dynamics to explore. If not every player knows the same thing, you enable emergent social dynamics like deception and conditional coordination.

But blockchains by design have open and transparent data layers. On the Bitcoin network, you can see a full record of all the transactions that have happened since the beginning of the system. So until ZK crypto was productized, the only games built on decentralized systems were very simple ones like CryptoKitties and other trading card games.

In 2019, we realized that we could use ZK crypto to make incomplete information games on the blockchain. Now, players can make moves while keeping their private information hidden; that is, a player doesn't need to know exactly where I am to verify that my move was valid.

Dark Forest revolves around a common strategy game mechanic and plot device called the "fog of war." You start off at a home planet in a little corner of the universe. Until you have explored some area of the map, you don't know where or whether other civilizations exist. This anxiety—not knowing what's out there, and not knowing who's seen you—drives a lot of the dramatic action.

How did Liu Cixin's Three-Body trilogy, and specifically The Dark Forest, inspire the storyline for the game?

This answer is fascinating, but contains mild/vague spoilers for the Three-Body trilogy. We've footnoted it, so scroll to the bottom to read!3

Dark Forest engages the central questions of politics, international relations, and human nature itself: for example, do you assume that everybody is power-hungry, or do you think empires can use diplomacy to create cooperative bodies like the UN? Since you don't have a formal background in these subjects, I'm curious how you derive your understanding of these issues.

That's a great question, and my answer is that I don't think we're capable of theorizing about it. We've built a very specific sandbox environment that may or may not bear resemblance to real-world situations. I think the best thing we can do as universe designers is to let people in, see what they do, and try to learn from that.

We've actually been quite surprised by a lot of player behavior. Coming in, we were anchored off Liu Cixin's Three-Body trilogy, where one of the implicit theses is that everyone is maximally suspicious and maximally cautious. Whereas in the Dark Forest game, a lot of players end up engaging in negotiations, trade, diplomacy, and even alliances.

It turns out that the communication channels available to players impacts their behavior. For example, we allow players to link their game accounts to their Twitter handles. One thing that organically emerged is that when players ran into each other, before taking any action, they would DM each other to determine if the other person was hostile, friendly, or might even be open to an alliance to wipe out another bigger player. We later moved the community to Discord and created channels where players can broadcast signals to each other.

The Dark Forest team tries to be fairly hands-off and non-prescriptive about how players should play. I don't think you can stop either players of a video game or players in the grand game of life from doing what they want. We’ve learned that people aren't going to bend to your theorizing.

Do you think that building Dark Forest has made you more optimistic about human nature?

The crypto ecosystem is very polarizing. You truly get the best and the absolute worst of people. For example, Satoshi and Vitalik are so committed to a vision of open technologies, and they've given up so much in the process. But any system that has economic incentives built in will simultaneously attract the most amoral people: the scammers, the grifters, the pump-and-dump shills.

We've been trying to be deliberate about constructing a community that self-selects as the former. So far, there aren't any financial mechanisms built into the game, though in the future, there almost certainly will be. And I've been pleasantly surprised that the game attracts developers who want to write code and share it with others—a lot of our third-party developers spend hours a day helping newbies write scripts or understand the Dark Forest plugin system. So this project has actually made me very optimistic for the decentralized universe community.

You can find more of bgu on his Twitter or Dark Forest's Twitter and blog.

Sign up for Reboot

🌀 microdoses

  • 💰 The following is provided for informational purposes only, and should not be relied on as legal, tax, or investment advice. (Or should it?)

💝 closing note

I've never been a gamer, so I turned to the Reboot Fellows to ask why they game:

  • Khoi (mentor, Fanhouse founder): Whereas fiction feels like worldbuilding via relationships and imagination; games feel like worldbuilding via roleplay and mastery. Also, when I used to make games, I'd find people do completely unexpected things. It’s harder to interpret fiction in a novel way from the author's intent than to find delight in a game that was unintended by the game designers.

  • Lucas (fellow, Brown 2023): Not my quote, but I thought of Bushnell’s Law, coined by the founder of Atari (Nolan Bushnell): “All the best games are easy to learn and difficult to master. They should reward the first quarter and the hundredth.”

Finally, if you could fill out Reboot's 1-minute feedback survey, that would be awesome. I personally read every single response!

To the moon,

—Jasmine & Reboot team

Disclaimer (Aug 2021): Reboot has since received a $5k grant from Dark Forest’s associated foundation. This newsletter piece was completed long before we asked for or received funding of any kind — in fact, the grantmaking body did not yet exist.


He has requested to be referred to pseudonymously in this interview.


For example, suppose I need to perform a complicated operation on some private medical records. Using these tools, I can give you an encrypted form of my data and tell you the program I want to run on it. Then you can do all these calculations—executing code—but at no point do you learn what these encrypted inputs actually are. You'll produce a result that looks like gibberish to you, then give it back to me to decrypt it. What I've essentially done is outsourced the computation to you.


How did Liu Cixin's Three-Body trilogy, and specifically The Dark Forest, inspire the storyline for the game?

The "dark forest" plot device in the Three-Body trilogy is the Fermi Paradox, which asks: if statistically, we think that other life exists in the universe, why haven't we seen any communications from them?

One proposed solution to the Fermi Paradox is that everyone acts maximally suspiciously. After all, you don't know if the other civilizations out there are malicious or benevolent. If they're malicious, giving any indication of who and where you are could pose an existential threat to your species. That makes keeping your location and existence secret of the utmost priority. The converse of that is that if when you find other civilizations, you're incentivized to broadcast information about them to the rest of the universe. It's like an informational weapon: if you broadcast their coordinates, someone else might take a preemptive strike, wipe out that civilization, and thus eliminate a possible threat.

So one of the key moments in the book—and one of the key feelings we tried to create in the game—is the feeling of discovering an alien race for the first time. You're like, Here's a planet with other intelligent life. Because of ZK cryptography, we don't know how quickly they're advancing or what their motives are; there's such a great cultural, linguistic, and space-time gap. Are you going to try to negotiate with them? Expose their coordinates? Attack them? What will you do when your response might have infinite repercussions on the fate of humanity?