The Last Lord: The first 100% on-chain MMORPG within the

Fractal Bitcoin and Bitcoin ecosystems

Over the past week, we’ve been working closely with the @BVMnetwork team to upgrade The Last Lord, making it the first 100% on-chain MMORPG within the Fractal Bitcoin and Bitcoin ecosystems.

Here’s how we made it happen:

This upgrade focuses on these two types of data: Real-time Data and Asset Data.

Real-time Data:

Includes map rendering data, player coordinate data, combat data, and data generated by players using flasks.

Asset Data:

Includes items sold by NPCs, consumables obtained by players through mining, fishing, gathering, monster drops, tokens, equipment, pets, costumes, etc.

Offchain Flow:

Player < — → Anti-Cheat System < — → Server

In large-scale MMORPGs, a massive amount of game data computation is generated. Due to the time sensitivity of the data, some of it is redundant and unnecessary to be on-chain. We refer to this type of data as real-time data, such as map rendering data, player coordinate data, combat data, and consumables like flasks used by players. Storing this data on server would not affect the game’s security or fairness, nor would it hinder the gaming experience. However, if stored on-chain, it would require synchronization every few seconds, leading to enormous gas consumption. Therefore, this data will be communicated via WebSocket with the server, reviewed by the Anti-Cheat System, and stored on the server.

Onchain Flow:

Player < — → Anti-Cheat System < — → Send transactions (txns) to The Last Lord Chain < — → Submit zk-proof (validity proof) to Fractal

Initially, we considered using Celestia, Near DA, Polygon, Avail DA, Filecoin, etc., as the DA layer. However, we quickly dismissed this idea as it seemed odd and less authentic. As an MMORPG running on Fractal Bitcoin, choosing Fractal Bitcoin as the DA Layer is clearly the best choice.

Asset data will be reviewed by the Anti-Cheat System, then the sequencer will send ZK Proofs to the smart contract on Fractal Bitcoin, with final data storage in the Fractal Data Availability layer, following these steps:

The player submits a transaction pre-request to the Anti-Cheat System; after review and approval, the server sends a proof of review. 2. The player submits a transaction to The Last Lord Chain L2 Sequencer. 3. The Last Lord Chain L2 Sequencer executes the transaction and provides a soft confirmation. 4. If the player chooses, they can force The Last Lord Chain L2 Sequencer to include their transaction. 5. The Last Lord Chain L2 Sequencer executes the block of transactions and sends it over to the The Last Lord Chain L2 Prover. 6. The Last Lord Chain L2 Prover creates a cryptographic proof of the block’s execution and sends it to the smart contract on Fractal Bitcoin. 7. The smart contract verifies that the proof is valid and all data has been submitted, then updates the rollup’s state in the contract. 8. The Last Lord Chain L2 Sequencer sends the block’s data to the Fractal Data Availability layer.

Through these steps, we will store game data, which we initially did not intend to put on-chain, such as basic equipment and consumables sold in stores. This is significant for an MMORPG. However, we also need to optimize algorithms and data structures to reduce data volume and transactions.

Player < — → CAT20, CAT721

The in-game token system will use the CAT20 @ProtocolCAT protocol. The in-game NFTs will use the CAT721 protocol.

By using the CAT20 protocol, players can not only claim in-game gold as on-chain assets and trade them on DEX but also participate in on-chain bank staking, guild governance, and more.

The in-game NFTs, such as equipment and pet systems, will be implemented using CAT721. This makes it possible to upgrade equipment, upgrade pets, and enhance pet attributes without destroying the current NFTs, achieving functionalities similar to those of NFTs using smart contracts.

Of course, in version 1, we will use the Ordinals protocol. Once the CAT721 protocol in Fractal is perfected, we will gradually migrate.

The above provides the technical details of this architectural change. We will continue to implement these features as development progresses. Stay tuned.

Make Bitcoin Fun Again!

Twitter: https://x.com/BitfunWTF Website: https://bitfun.wtf Game Twitter: https://x.com/TheLastLord_BTC Game website: https://thelastlord.games/ Bitcoin Assets Airdrop Checker: https://whitelist.thelastlord.games Community: https://t.me/bitfunwtf Whitepaper: https://docs.bitfun.wtf/ Medium: https://medium.com/@bitfun.wtf Github: https://github.com/bitfun-wtf Wiki: https://wiki.thelastlord.games