A Comprehensive Introduction of Fully On-Chain Games

What is a Fully On-Chain Game?

Unlike the common GameFi that puts props and assets on the blockchain, a fully on-chain game stores all game logic and data on the blockchain. Take the simple “card drawing comparison” chess game as an example, common GameFi is good at tokenizing entrance tickets, chips, etc., turning them into NFTs or cryptocurrencies. But in the context of a fully on-chain game, the logic of “randomly issuing a card to a player, then comparing the size of the numbers represented by the player’s cards, and the larger one is the winner who wins the chips” is put on the blockchain, and the whole process is open and transparent.

Initially, fully on-chain games were loved by a group of Web3 native developers and players, but with the explosion of fully on-chain games like Dark Forest, more and more people have recognized the incomparable advantages of fully on-chain games over traditional GameFi and off-chain games. The advantages are as follows:

Openness

Fully on-chain games are deployed on the blockchain, opening the game entrance to everyone. It is not limited by country, gender, age, etc.

Transparency

Due to the game logic being put on the blockchain, the possibility of cheating in the game is extremely low, and players can observe the game operation status through the deployment of contracts on the blockchain.

Asset Ownership

The assets obtained by participating in fully on-chain games are also on-chain assets, which players fully control and can freely transfer.

Community-oriented

Fully on-chain games pay more attention to community development, most of which are governed by DAOs, and the needs within the community will continuously improve the game.

Sustainability

Theoretically speaking, the code is deployed on the blockchain as smart contracts, and the blockchain is equivalent to a server. As long as the chain maintains normal use, players can experience the game at any time without worrying about the game’s lifespan.

Composability

In traditional games, the “game logic” that is on-chain in fully on-chain games belongs to the backend code. Therefore, it can borrow the difference of the game UI of different front-end pages, and even realize the function of multi-module games by connecting different fully on-chain game contracts to a front-end page.

Fully On-Chain vs GameFi vs Traditional Games

For easy comparison, we present the differences in table form:

From the comparison above, it can be seen that the fully on-chain games, due to their complete deployment on the chain, have more decentralized characteristics of Web3 in terms of data, assets, financing, and servers. However, the performance of the blockchain also limits their game operability and gameplay, and the fully on-chain users have not yet expanded out of Web3.

Industry Infrastructure

The development process of fully on-chain games is similar to that of traditional game development, but due to the on-chain game logic, it also has its unique technical stack. The core infrastructure of fully on-chain games is mainly the fully on-chain game engine and blockchain. Of course, technologies such as AA and zero-knowledge proof can also be applied to the fully on-chain game stack. Before discussing specific fully on-chain game projects, we need to understand the infrastructure in the industry (below the application layer).

Fully on-chain game industry level（source：IOSG’s Medium ）

Blockchain

In fully on-chain games, blockchain serves the role of a server, with game logic deployed on the chain. Users need to connect with a wallet to play. Currently, most fully on-chain games are distributed on Ethereum and Layer2. When choosing a public chain for deployment, multiple factors to be considered:

1. Programmability of the public chain
   In the early days of the development of fully on-chain games, Ethereum was chosen by many early fully on-chain games as the most powerful platform for smart contract programming. Now, the mainstream Layer1 and Layer2 platforms have made different optimizations for Dapp development. Aptos and Sui, for example, have optimized the programming experience at the programming language level. Public chains that are more developer-friendly and optimize the process of users calling contracts are more likely to be favored by public chain developers.

2. Network performance
   Players need to call contracts and get chain data feedback when playing games, which requires a certain level of chain performance. For instance, in a multi-user real-time game, multiple signatures are needed in a single game round. If the network is very congested, it can lead to a poor user experience. Currently, the TPS of Solana and Ethereum Layer2 can meet the underlying needs of existing fully on-chain games.

3. User volume
   The Web3 nativeness of fully on-chain games implies a higher user threshold. Furthermore, the gaming process may involve on-chain activities such as game prop trading. Therefore, choosing a chain with a higher number of users and better liquidity for deployment can increase the likelihood of success for fully on-chain games.

4. Network effects of public chain application layer
   After the launch of Fully On-Chain games, NFT marketplaces and DeFi protocols can substantially enhance the liquidity of in-game assets and native tokens, thereby attracting a larger user base. Concurrently, various service providers, including game engine developers, will tailor their offerings to be compatible with different blockchain architectures. It stands to reason that a high-caliber blockchain will not only excel in gaming applications but also pave the way for the thriving development of other decentralized applications (dApps), thereby maximizing network effects at the application layer.

Blockchain Game Engine

In traditional development processes, game engines like Unreal, Unity, and Phaser provide the basic building blocks of games, such as controlling movement, 2D and 3D rendering, object collision detection, sound, color, scripting and other physics engines, and even include server-client architecture, PC / game console / mobile frameworks and other one-stop service features.

In fully on-chain games, because the game state will be completely stored on the blockchain, game engines designed for on-chain games have emerged.

The first one developed for the Ethereum ecosystem was the MUD engine launched by Lattice, and then gradually other engines appeared for different ecosystems and using different programming languages, such as DojoEngine for Starkware, and Curio’s Keystone, Argus, etc.

Middleware

AA

AA is the abbreviation for “Account Abstraction.” Unlike the common encrypted wallets obtained with private keys and mnemonic words, wallets using account abstraction are programmable contract wallets. It distinguishes the logic and status of the account, allowing the creation of accounts with customized transaction verification and execution rules. AA has improved the user experience in many aspects and has a rich range of application scenarios, such as social recovery, multi-signature, and gas fee-free transactions.

By leveraging AA technology, Fully On-Chain games can resolve issues that degrade the user experience, such as the need for repetitive signatures and the requirement to use a specific wallet, thus achieving more user-friendly interactions.

Random Number

Random number generation technology is a commonly used technique in game development. Its basic principle is to generate a pseudo-random number sequence through a specific algorithm and seed. In games, random numbers can generate random events, random terrains, and random items, enhancing the game’s playability and entertainment value.

Oracle projects like ChainLink can provide random number components, and developers can also directly use blockchain-based random number generators, directly using the block hash values in the blockchain as random number seeds, thereby generating verifiable random numbers. Random numbers can bring more transparent and fair gameplay to fully on-chain games.

Zero-Knowledge Proof

Zero-knowledge proof is a cryptographic technology that can be used to prove the truth of a proposition without revealing the content of the proposition. This technology is widely used in areas such as protecting user privacy and data integrity. In fully on-chain games, zero-knowledge proof can be used to verify actions or events in the game, such as players completing tasks or challenges. Using zero-knowledge proof technology, players can prove that they have completed a task or challenge and receive corresponding rewards without revealing privacy information, and without the need to send related data to the game server, thus improving security.

Popular Fully On-Chain Games

Darkforest

Dark Forest is a fully on-chain MMO space conquest real-time strategy game based on the “Dark Forest Law”. The game’s background is set in a universe like a dark forest, where each civilization is a gun-toting hunter. They initially don’t know about each other’s existence, but once they discover each other, the most rational thing to do for self-preservation is to eliminate each other. The map and the opponent’s location in the game are hidden in the cryptographic fog of war, and players need to gradually reveal more parts of the universe through actions. Each action is recorded on the blockchain, and the player’s coordinates remain hidden from opponents.

DarkForest Game Screenshot（Source：Technology Review）

Dark Forest employs Fully On-Chain technology and zk-SNARK to create its unique gaming experience, where all game rules and logic are deployed on the blockchain as smart contracts.

Wolf Game

Wolf Game is a unique game based on the Ethereum blockchain. In this game, players can purchase and own non-fungible tokens (NFTs) of different characters, including wolves, sheep, and farmers. The goal of the game is to collect WOOL tokens by managing the actions of the characters.

There is only a limited supply of land in the entire game ecosystem, each piece of land is an NFT. The rarity of wolves determines their chance of stealing new castings, players can obtain WOOL tokens by shearing or removing mortgages, and can use these tokens to cast new animals. At the same time, the game also introduces a risk protocol, which requires players to balance benefits and risks.

Wolf Game Style Display（source: Wolf Game Official Website）

In the early stages of the game, it was planned to use L2 technology, that is a second-layer expansion solution, to increase transaction throughput and reduce transaction costs. To accelerate the development and design improvement of the game, after redesign, the game adopted a Web 3-Web 2 hybrid architecture, that is, the gameplay will take place off-chain, while asset ownership will be on-chain.

Loot Survivor

Loot Survivor is an adventure experimental game based on the Loot style, providing players with a unique gaming experience through the Play 2Die economic model. The game is deployed on StarkNet for testing and is jointly developed by team members from Bibliotheca DAO, DoJo, and Guildly.

The core gameplay is exploration, combat, upgrading, and trading. Players need to create a wallet and connect the wallet, and then start the adventure. In the game, players will face various challenges and enemies, and need to use strategies and skills to survive and win. Players can explore various locations, defeat bosses, collect rare items and equipment, and trade with other players to enhance their character’s abilities.

Loot Survivor Game Interface（Source: Official Website）

In Summary

From the three typical full-chain games shown above, we can see that the current Web3 Fully On-Chain games still have relatively limited gameplay, focusing mostly on strategy and simulation genres. The quality of special effects and animation is poor compared to mainstream games like ‘Elden Ring,’ ‘League of Legends,’ and ‘Call of Duty.’ Given the niche audience and the entry barrier of Web3, Fully On-Chain games face significant challenges in user acquisition.

Challenges of Fully On-Chain Games

Limitations of the underlying blockchain technology

Because blockchains are not exclusively for on-chain use, Fully On-Chain games still face the issue of network congestion. On chains with lower TPS (Transactions Per Second), the speed of game operations may also be delayed due to the time it takes to confirm the contract state on the chain. This also means that MOBA, FPS, and other multiplayer real-time online games cannot be implemented on the blockchain.

Limitations of complete transparency

Since the game logic is on the chain, some game plots can also be publicly visible on the chain, which is not conducive to the design and gameplay of setting hidden levels in the game. This also leads to potential cheating issues. When players send transactions to the public memory pool, if the transactions are submitted in a readable format, there may be behaviors of players cheating. This means that any observer of the memory pool may know the opponent’s next move in advance and take corresponding actions to counterattack.

High threshold

Users in fully on-chain games need to sign and confirm various operations on the chain, which not only reduces the fun of the game but also brings a high threshold to enter the game. Players must master enough Web3 knowledge, such as using wallets, signing contracts, etc., to enjoy the game.

Separation of assets, data, and users

The current market situation with multiple chains leads to Fully On-Chain games primarily being deployed on a single chain. Players cannot trade assets between different chains, and new users often need to perform cross-chain asset transfers before trying the game. The game also cannot attract users who are not on its hosting public chain.

Prospects of Fully On-Chain Games

Despite some flaws, with the development of technology and the improvement of infrastructure, fully on-chain games may usher in a “golden age”.

Scalability and the Development of RaaS

Regarding the performance issues of blockchain, solutions such as Layer2 and RaaS have already emerged. Today, many second-layer scaling projects are dedicated to scalability issues. Teams with sufficient funds can use general L2s such as StarkNet or Arbitrum Nova, or customized L2 frameworks like OP Stack for specific use cases, to build L2 expansion layers. They can use Caldera, Conduit, Eclipse, Alt Layer, and other RaaS (Rollup as a Service) according to the needs of custom application chains.

Increase in Infrastructure

Whether it is the development of blockchain game engines or the upgrade of middleware technologies like AA, fully on-chain games will experience a new development in gameplay and user experience. DeFi and NFT Market, which are not directly related to fully on-chain games, will also indirectly boost the development of fully on-chain games. On Layer2s like Starknet, we have already seen an ecosystem network that runs through the upstream and downstream from game engines to game stores, setting an example for other public chains.

Improvement in User Experience

The future fully on-chain games will lower the user threshold after integrating technologies like AA and cross-chain bridges. In the future, users may only need to log in with their email or social media accounts to start the game. During the game, they may only need to sign once or not at all to enjoy the whole game. More Web3 native operations in the game can be abstracted as the backend, while the frontend provides a silky gaming experience similar to Web2.

Conclusion

In summary, Fully On-Chain games return ownership to the players and make the game logic publicly transparent on the blockchain, aligning well with the decentralized spirit of Web3. They offer unprecedented levels of openness and freedom, allowing anyone to extend and modify their blockchain-based world without requiring permission. However, because they are closely tied to the blockchain, they are limited by the chain’s performance and infrastructure. As it stands, Fully On-Chain games are more suitable for card games and turn-based strategy games where contract interactions are less frequent. The design philosophies of focusing on community engagement, frontend-backend separation, and returning asset ownership to players inspire new design ideas for both Web3 applications and traditional games. As blockchain technology and middleware like AA continue to evolve, Fully On-Chain games will become increasingly suitable for various types of games and gradually offer a user experience comparable to Web2 games.