Announcing OPCraft: an Autonomous World built on the OP Stack

Building an entirely on-chain crafting-based voxel game using the OP Stack.

Announcing OPCraft: an Autonomous World built on the OP Stack

A secret little world…

Over the last few months, we at Lattice have been working on an exciting technical collaboration with the Optimism team.

You may have seen glimpses of it on Twitter—tweets with a wall of emojis referencing autonomous worlds or screenshots of funny looking structures in the foreground of a blocky landscape. Or maybe you overheard tales from your friends who were at Devcon about an exciting new on-chain game.

Today we’re officially unveiling OPCraft: a fully on-chain 3D voxel world built with MUD (our open-source on-chain game engine) on top of the OP Stack (Optimism’s modular rollup architecture).

So what is OPCraft?

OPCraft is an Autonomous World—a fully on-chain virtual space where every single aspect of the World—every river, blade of grass, and patch of snow sitting atop the mountain ranges—exists on-chain, and every single action in the World happens as an Ethereum transaction.

Just like other crafting-based voxel Worlds, you can explore procedurally generated landscapes, mine ores, place materials, and craft new items. Players can create majestic architectures, erect monuments, and terraform the land; either alone or collaboratively.

OPCraft runs on an op-chain; meaning the blockchain is mainly being used towards updating the World as players modify it. Just like a normal rollup, developers can deploy smart contracts on this chain and anyone can run a node in order to access it.

OPCraft’s network runs on Optimism’s OP Stack architecture, with simple adjustments made for higher throughput and shorter block times.

Why on-chain Autonomous Worlds?

Autonomous Worlds unlock new affordances not found with traditional centralized and opaque game servers. Here are some examples, in order of craziness:

  1. Custom clients: Picture the OPCraft World in incredible 4K definition, beautifully ray traced and rendered by Unreal Engine 5. Or picture an enterprise-grade project management UI for managing and automating mining operations in OPCraft… Because the World lives entirely on-chain, anyone can go build a custom client that interacts with it without needing special permissions, as long as the inputs and outputs conform to the protocol. Just like a DeFi protocol that can be accessed through many different portals, OPCraft doesn’t have a canonical representation. We can’t wait for someone to build a client replacing all characters with anime characters, or a complete rewrite with beautiful shaders.
  2. Interoperability: All the rules and data of OPCraft lives on-chain; smart-contracts can interact with OPCraft just like regular players, or retrieve specific information from the World. Imagine a smart contract that pays you 1 ETH for every diamond block that you mine for it, or a smart contract that etches your name into its stone monument in the World for a price. Given OPCraft runs on-chain, developers can deploy smart contracts that drive trustless player economies, or even entire new game features. Who is going to build the OPCraft AMM that can only be accessed from a special cave at the center of the World 👀?
  3. Augmented reality: AR, but not in the way you think. Expanding on the entities and rules of the World, developers can create additional properties that augment the World. For example, a developer can create a “team” property attached to objects placed by players. Now players who choose to opt-in to this augmented version of the World can see which team a building belongs to and receive NFTs when they help their team take over new areas of the World. This enables exciting meta-games, rivalries, and drama completely driven by players and developers.

We believe fully on-chain Autonomous Worlds are the logical next step to crypto gaming; and we hope that OPCraft—along with the release of the technology it was built upon—kickstarts an on-chain gaming renaissance.

Taking it one step further…

Many traditional multiplayer games are shut down when the company operating the game runs out of money or frequently change the rules in a way that heavily penalize the existing user base.

An Autonomous World, on the other hand, has the ability to forego having an owner that can alter the past and change the rules of the World. Additionally—by virtue of running on a blockchain—the World can remain alive for as long as a single full node stores its entities and enforce its rules.

It is important to note that OPCraft—currently a proof-of-concept—is not completely ownerless. It runs on a custom Optimism testnet that will only run for approximately two weeks. However, just like current rollups, it has a credible path towards autonomy and permissionlessness.

OPCraft is open source—both contracts and clients—and we hope to see motivated players deploy their own persistent World on any EVM-compatible chain, and soon on custom instantiations of the OP Stack in order to unlock even more player throughput.

How did we build OPCraft?

OPCraft was uniquely enabled by two new technologies:

  1. Optimism’s OP Stack: a set of modules that can be easily plugged together to create your own chain.
  2. The MUD Engine: an open-source engine for creating Autonomous Worlds, built by Lattice.

Using MUD and the OP Stack, it only took us a little more than a month to build OPCraft from the ground up.

For those looking for a more in-depth technical write-up on how we built OPCraft, we’ll be releasing an article on the topic very soon at Follow @latticexyz to get notified when it comes out.

How do I play?

The OPCraft World is now publicly available at this link.

The World will be available for approximately two weeks for you to mine, build, and craft to your heart’s content. On Halloween (31 October at 23:59 UTC) the World and the chain will be frozen in time, immortalizing any structures, art, and monuments you’ve created.

So get out there, join our Discord channel, and craft something cool!

See you in OPCraft!

If you're a project or developer interested in building on the OP Stack, get in touch.