Observing Fully On-Chain Games

TL;DR:

• A fully on-chain game is a game that maximally embraces decentralization, characterized by
  • Storing game data on the blockchain
  • Deploying game logic and rules as smart contracts
  • Open-sourcing
  • Designing the game to be client-agnostic
  • Employing digital assets
• One example of a fully on-chain game is Dark Forest, a decentralized MMO and RTS space-conquest game built with zero-knowledge cryptography
• The primary benefit of building web3 games fully on-chain (as opposed to partially on-chain) is permissionless interoperability, as players have new and varied means to participate and developers benefit with permissionless modding without deplatforming risk

What are Crypto-Native /  Fully On-Chain Games?

Web3 / blockchain games are games that have some (but not necessarily all) of their core mechanics handled by the blockchain. Some examples of web3 games include Axie Infinity, Splinterlands, and Sorare.

Currently, the “web3” components in the majority of web3 games are largely additive to (and not a replacement for) core tech used to build web2 games. Specifically, developers are incorporating wallets and leveraging NFTs and fungible tokens as in-game assets, while game state and logic are conducted off-chain.

While largely experimental (and ever evolving) today, “crypto-native games” or fully “on-chain games” offer a glimpse of how web3 games may evolve from their current instantiations. According to Brian Gu from 0xPARC (and developer of Dark Forest), a crypto-native game is defined as “a game that maximally embraces the architectural patterns and ethos of blockchain application development” and are characterized by the following properties:

• The source of truth for game data is the blockchain (i.e., all the meaningful game data – not just asset ownership – are stored on the blockchain)
• The game logic and rules are implemented via smart contract (enabling the game to execute permissionlessly)
• The game is developed in accordance with open ecosystem principles (i.e., the underlying smart contracts and game client are open-source)
• The game is client-agnostic (i.e., the game will still be playable should the core developer-provided client be deprecated)
• The game embraces real-world value digital assets (e.g., cryptocurrencies and NFTs)

Examples of fully on-chain games include Dark Forest, Conquest, Mithraeum, Treaty, and Realms. These games tend to be strategy games (e.g., 4X, RTS) with lightweight game design, which permit fast development cycles and serve as proof of concepts for the general viability of fully on-chain games.

An On-Chain Game Case Study: Dark Forest

To illustrate what all this looks like in practice, let’s take a look at Dark Forest, a decentralized MMO (massively multiplayer online) and RTS (real-time strategy) space-conquest game built on the Gnosis Chain with zero-knowledge cryptography.

Dark Forest Overview

In Dark Forest, players explore and conquer planets in a procedurally-generated universe (each coordinate in the universe has a probability of spawning a planet, and each planet would randomly be assigned various attributes). Dark Forest functions as an incomplete information game (a game where players may not know the full state of the world), as players start the game at their home planets with a fog of war surrounding them. Through the players’ local computing power to compute the hash for each coordinate, the rest of the universe becomes visible.

This fog of war is achieved by leveraging zkSNARKS that validate each player’s moves on the blockchain without revealing that information to other players. In other words, players don’t submit the coordinates of planets they conquer to the smart contract but instead commitments to their planet locations (by hashing the planet coordinates), along with zero-knowledge proofs that the hashes are valid, effectively keeping planet locations secret.

Dark Forest is a Crypto-Native, Fully On-Chain Game

Dark Forest adheres to the definition of a crypto-native game above, as the:

• Game data is in the blockchain:  While the locations of each player’s planets are private and hidden from each other, the hashes of each player’s planet coordinates are submitted to the Gnosis Chain
• Game logic is implemented via smart contracts: Dark Forest’s game logic and rules are deployed as smart contracts
• Game is developed with open-ecosystem principles: Dark Forest’s frontend web client, smart contracts, and zkSNARK circuits are open-source, and third-party developers can develop plugins (shared Javascript code to allow players to customize their frontend gameplay experience) and deploy their own smart contracts (e.g., the Sophon Reveal Marketplace provides a contract that lets users sell certain map information for a fee). Players can also develop bots to programmatically play Dark Forest on their behalf
• Game is client-agnostic: Any third-party developer can implement alternate clients by forking the core dev’s existing React/WebGL client frontend and editing the client to their liking
• Game embraces digital assets: Dark Forest uses xDai (to pay the gas fees for each move) and NFTs (that can be deposited to a planet to change its attributes)

Benefits to Having Games Fully On-Chain

The primary benefit of games becoming fully on-chain (as opposed to partially on-chain) is permissionless interoperability. We can see this benefit across both players and developers:

• Players have new and varied means to participate in a game: Any player, bot, or smart contract can interact with the game programmatically, enabling experiences such as permitting a collective of players to play through a DAO and allowing for novel player-to-player interactions (e.g., on-chain social contracts, allowing players to selectively opt-in to impose some logic among themselves without breaking the underlying game rules or impacting other players)
• Developers benefit with permissionless modding without deplatforming risk: Third-party developers can modify the game experience by customizing client-side frontends and adding in new core gameplay features to a game without having to get permission from the core developers (e.g., add a third-party marketplace by deploying an escrow or marketplace contract that interacts with the core game contract) and without fear of deplatforming (as the game logic and state are immutable on the blockchain)

Looking Forward

While the broader web3 gaming sector is emerging, we are at the onset of fully on-chain games. Since its inception in 2019, Dark Forest has had 10K+ players globally play the game (as a rough point of comparison, Axie Infinity had 2.7M average daily active users during its peak in November 2021). Some factors that may lead to increasing player adoption for on-chain games (and more broadly, web3 games) include improving UI/UX and game architectures (e.g., implementing a key management system to save users from signing transactions too often), introducing granular, game-specific on-chain data pipelines and analytics, ensuring client-side security, and the introduction of more interactive games.

It’s fairly early to say whether on-chain games achieve broad-based adoption or even become the paradigm of web3 gaming. Perhaps sometime in the future we would see the next breakout web3 game be created by third-party developers building off from an on-chain game, layering their own UI/UX and extending gameplay functionality by deploying custom smart contracts (not too dissimilar from the modding that kickstarted Dota and Counter-Strike). Perhaps on-chain gaming will simply serve as proof of concepts for autonomous worlds. We’ll just have to build around and find out.