Dark Forest: The Space Game That Hid a Universe Inside Ethereum

Imagine a strategy game where the server is a glass box. Everyone can read every line of code and every move ever made. Now imagine trying to build fog of war inside it, so that nobody knows where your planets are. That sounds impossible. In 2020, a small team did it anyway, and called the result Dark Forest.

Dark Forest was announced on 2 August 2020 as a decentralised, persistent real-time strategy game running on Ethereum. Its first beta, version 0.3, opened on 7 August 2020 on an Ethereum test network. It ran for one week, was invite-only, and offered a 1,024 DAI prize pool (DAI is a dollar-pegged token). It never became a mainstream hit. It became something more influential: the game that convinced developers a whole game, not just its items, could live on a blockchain.

A universe with no server

Most "blockchain games" keep the game itself on ordinary servers and use the chain only for items, like a cloakroom ticket for your sword. Dark Forest flipped that. The rules, the map, the planets, the moves and the winner were all handled by smart contracts on the chain. There was no company server deciding what happened. If the team switched off their computers, the universe would still exist.

You play by exploring a procedurally generated cosmos, finding planets, and sending energy between them to capture more. Planets grow, produce resources and can be upgraded. Other players are out there doing the same, and sooner or later your empires collide. It's a little like a slow, browser-based cousin of classic space 4X games, except every order you give is a signed blockchain transaction.

That design has a famous problem. A public blockchain is public. If your planet's coordinates are stored on Ethereum, any rival can read them.

How you hide in a glass box

Dark Forest's answer was zero-knowledge proofs, specifically a kind called zkSNARKs. A zero-knowledge proof lets you prove a statement is true without revealing why.

Here is the trick in plain terms:

• When you move to a planet, you don't publish its coordinates. You publish a hash of them, a scrambled fingerprint that can't be reversed.
• Alongside it, you submit a proof that the move is legal: that the hidden planet really exists where you claim, and that it's within range of where you came from.
• The smart contract checks the proof, accepts the move, and learns nothing about where you actually are.

To find other players, you have to search. Your computer explores the map by hashing coordinates region by region, testing which ones contain planets. The more computing power you throw at exploring, the more of the universe you see. Fog of war, in Dark Forest, is not a graphic effect; it is a mathematical fact.

Chess is the classic example of a game with no hidden information: both players see everything. Dark Forest's launch post made the same contrast. Adding hidden information to a fully public system was the breakthrough.

Players who wrote code instead of clicking

Because everything was on-chain and open, Dark Forest players could do something most strategy games forbid: they could write their own tools. The game supported community plugins, and dedicated players built scripts to automate exploration, manage dozens of planets and plan attacks. Some of the strongest players were, in effect, programmers running bots.

That divided opinion. Some saw it as cheating by another name. Others saw it as the whole point. In a world where the rules are public code, the game expands to include anything players can build on top of it. Fans started calling this kind of design an autonomous world: a game universe that keeps running on its own rules, which anyone can extend.

From one game to a movement

Dark Forest's biggest legacy is the people it pulled in. Developers around the project helped form 0xPARC, a research group focused on applied zero-knowledge cryptography and on-chain games. Out of that circle came tools and teams that pushed the idea further: frameworks for building on-chain worlds, such as MUD on Ethereum and Dojo on Starknet, and a wave of experiments in "fully on-chain games" (FOCG), where the whole game state lives on a blockchain.

The approach has real drawbacks. Fully on-chain games are slow by gaming standards, because every action waits for a block. They can be expensive when the network is busy. And because the code is public, any bug is visible to everyone, including attackers. Players also have to deal with wallets and transactions, which is a hard sell compared with simply pressing Play.

But the appeal is just as real. A fully on-chain game can't be shut down by its publisher, because there is no server to switch off. Anyone can build a new interface, a new map or an add-on without asking permission. And the results are verifiable: nobody can quietly change the rules.

Why it still matters in 2026

Dark Forest never had a big marketing budget, a token or a flashy trailer. Its rounds were small, and its players were mostly developers, researchers and crypto enthusiasts. Yet more than six years later, it is still the reference point whenever someone pitches an on-chain game. It proved three things that the rest of web3 gaming still argues about:

1. Blockchains can hold more than items. A whole game can run on one. 2. Privacy is possible on a public ledger. Zero-knowledge proofs can hide what needs hiding. 3. Open rules invite players to build. The line between player and modder blurs.

It also showed the limits. Most players don't want to run bots or pay for transactions, and most studios can't afford to make every move a blockchain transaction.

By the numbers

• 2 Aug 2020: Dark Forest announced
• 7 Aug 2020: first beta (v0.3) opens, for one week
• 1,024 DAI: first-round prize pool
• 0: coordinates revealed on-chain when you move, thanks to zero-knowledge proofs

WGC's take, and what to play next

Dark Forest is the indie art-house film of blockchain games: rarely played, often cited, and much more interesting than most of what followed with bigger budgets. If you want to understand what "on-chain gaming" is meant to mean, start here rather than with any token chart.

What to look at next: the frameworks that grew from this idea. Our explainers on MUD and autonomous worlds and Dojo and on-chain games on Starknet pick up the story, and our piece on Loot shows another 2021 experiment in letting players build the game themselves.