At GDC, we announced the next major rollup in Immutable’s offering: Immutable zkEVM. If you’ve spent some time in the blockchain gaming space, Immutable and Polygon partnering to launch a dedicated EVM-compatible chain was huge news - and as we prepare to launch Immutable zkEVM’s testnet, it’s time to pull back the curtain. Join our CTO Alex Connolly in this Immutable zkEVM technical deep dive.
As Immutable’s CTO, the most common question I’m asked by new studios is “why should I build my game on Immutable zkEVM over any other chain?” Our answer is simple:
- Immutable’s Platform is the best-in-class for building web3 games
- Immutable zkEVM is a blockchain designed for games, not a general-purpose chain
- Immutable’s Ecosystem is the largest and most impactful in web3 gaming
Immutable's Platform is the best-in-class for building web3 games
Building on Immutable gives you access to the Immutable Platform, a one-stop-shop toolset for creating mainstream-ready web3 games. Many blockchains consistently tout innovations they’ve made at the protocol layer (e.g. transaction parallelisation, first-class objects). Unfortunately, these capabilities are not useful unless games also have access to a strong selection of “up the stack” tools to help them build great games, quickly, with a compelling end-to-end user experience. At Immutable, we’re building both the blockchain and platform layers to ensure the player and developer experience is consistently excellent.
For the simplest example, look no further than wallet infrastructure: the best underlying blockchain doesn’t matter if your transaction experience destroys purchase conversion rates. To solve this, we built Immutable Passport, the leading wallet for web3 games with an onboarding and transaction experience which feels like signing in and purchasing with Google or Apple.
Crucially, Passport is different to the many custodial wallet implementations games have turned to over the past 12 months, because Immutable Passport is not bound to a particular game or marketplace, but can travel with users across the entire Immutable ecosystem. If a user has funds (through an on-ramp or by selling an asset), those funds will be available in all games and marketplaces, massively reducing purchase friction.
Immutable also understands that purchase flow conversion is massively important to games. The friction of on-ramp or bridges, needing to swap currencies, popups at the wrong time - all these will harm monetisation at scale, so we built Immutable Checkout to facilitate a smoother experience across all web3 wallets. We’re also focused on reducing the frequency of scams and hacks through better safety features.
Immutable’s platform also contains a powerful suite of development tools to accelerate your engineering team, including:
- Enforceable Royalties for games across all marketplaces on Immutable zkEVM
- A powerful Indexer with game-focused aggregations and webhooks for custom notifications
- Global Orderbook and Marketplace Network to allow games to build custom marketplaces without a liquidity penalty
- Economy Tooling to help games launch and manage their economies, including Crafting and Inventory tools
- (Coming Soon) Primary Sales tooling to assist games with running sales (either web3-style drops or continual sales)
Today, many web3 games build limited versions of these products themselves. However, the investment required to replicate, maintain, and scale this tooling is substantial, and our strong view is that individual games need to focus on building fantastic games! Immutable’s product development improves all games across our platform simultaneously, creating a huge economy of scale and allowing us to continually re-invest as usage grows.
In order to service games targeting mainstream scale, we have also made substantial investments in resilience, security and compliance. The Immutable Platform already services tens of millions of production API requests every day, and we are committed to becoming the backbone platform for many planet-scale web3 games.
Put simply, Immutable’s platform tooling massively reduces the amount of time and effort to bring games with web3 ownership mechanics to a mainstream audience. This platform is only available on Immutable’s rollups, and is a huge reason games choose Immutable zkEVM over any other chain.
Immutable zkEVM is a blockchain designed for games
Secondly, Immutable zkEVM is a blockchain designed for games, not a general-purpose chain. Most blockchains are designed as all-purpose chains, which requires them to make a number of important design compromises. With Immutable zkEVM, we’ve made several deliberate design decisions to support the particular needs of games.
Firstly, we chose to build an EVM-compatible chain. The EVM has enormously powerful network effects in terms of:
- The number of games and other applications already built on EVM chains. EVM chains currently represent more than 90% of DeFi TVL.
- The number of tools and marketplaces which are EVM-native and can instantly support new EVM chains
- The number of developers who are capable of writing production-grade smart contracts in Solidity vs. other new programming languages like Cadence or Move.
To compete with the EVM ecosystem, as we outlined in our Ground Up zkEVM Guide, new ecosystems need to not just create and maintain a huge swathe of parallel tooling, but develop fast enough to keep up with the snowballing Ethereum ecosystem. Immutable zkEVM is able to benefit from the collective development efforts of the entire Ethereum ecosystem, and will have a robust ecosystem of ready-made third party tools available from Day 1. While non-EVM chains have more opportunities for differentiation (e.g. native account abstraction), they will face an enormous uphill battle to compete with the EVM developer ecosystem.
Immutable has first-hand experience with non-EVM chains: Immutable X is our custom rollup focused exclusively on ERC20/ERC721 minting/trading/transferring. Immutable X is incredibly powerful, but its custom nature has forced us to work extremely hard to gain support from third-party tools. If EVM compatibility and third-party tools aren’t important to your game, you should take advantage of the full power of a customized rollup and use Immutable X - walking the middle ground by choosing a non-EVM chain is a risky strategy.
Second, we chose to be an Ethereum zk-rollup, rather than an independent blockchain. In A Guide to NFT Platform Security, we outlined why zk-rollups have long term security advantages over other approaches. As the $650m Ronin/Axie bridge hack showed, the impact of not prioritizing security can be catastrophic for games. Being a zk-rollup means Immutable zkEVM can benefit from Ethereum’s security while minimizing inflationary token rewards as validator incentives. This enormous saving can be passed on directly to users of the platform through reduced fees.
To achieve this, Immutable zkEVM uses Polygon Zero as our prover. Polygon Zero is a Type 1 zkEVM prover, which means it is fully Ethereum-equivalent and developers won’t need to modify their Ethereum contracts for zkEVM. The reduced speed of proof generation and L1 publication will increase transaction costs, but we expect these fees to reduce significantly over time through developments like Plonky-2, parallelisation, recursive proving and eventually custom hardware. Importantly, ZK-rollups produce substantially reduced fees compared to Optimistic rollups, and support moving funds/assets back to L1 faster than 1 week without harming capital efficiency.
Next, we run this chain as a Validium, rather than publishing all data to Ethereum. This allows us to significantly reduce the per-transaction gas cost to users, albeit with important trade-offs around disaster recovery. Polygon zkEVM publishes all data on chain, which increases the base transaction cost substantially - we expect Immutable zkEVM to be ~90% cheaper at launch. After EIP-4844, which will substantially reduce the cost of on-chain blob data storage, we’ll consider alternative data availability strategies.
Third, we use a customized deployment of Polygon Edge as the client software for the chain. Edge is the product of a years-long investment by Polygon in creating a brand new, high performance EVM client implementation. Immutable has made a number of customisations and configuration changes to achieve an overall throughput comparable to Polygon PoS.
During our initial launch, Immutable will be the only sequencer on Immutable zKEVM. Over time, other validators will join, carefully balancing the scalability tradeoffs of a larger validator set with the improvements to resilience and decentralization. This is consistent with the progressive decentralization strategy of all major rollup teams, including Arbitrum, Optimism and StarkNet. Importantly, even if Immutable were fully compromised, no invalid transactions could be executed on L2 due to the requirement for L1 validity proofs - your users’ funds will be safe regardless.
In the future, games which need specific customisation or increased horizontal scale will have access to their own dedicated rollups through Polygon Supernets with full Immutable platform support. However, building a new chain from scratch requires a substantial investment in bootstrapping local network effects, and our recommendation is that most games begin on a shared blockchain and consider an appchain once they have a clear need.
There is no perfect design for a gaming rollup - many games continue to choose Immutable X due to its gasless transactions and synchronous APIs. However, for games that need smart contracts, Immutable zkEVM is the product of years of investment in building a chain custom-designed for their specific needs. We’ll be providing even more detailed chain specifications in an upcoming blog post.
The Immutable Ecosystem is the largest and most powerful in web3 gaming
Most importantly, Immutable has created the most powerful ecosystem for web3 games, maximizing their chance of long term success. Successful web3 games require not just powerful foundational technology, but also an ecosystem which is capable of accelerating a game through development and launch.
So far, more than 150 high-quality games have already committed to the Immutable ecosystem, and Immutable is investing heavily in growing that number. This contributes to an incredibly powerful network effect: as each of these games launches on Immutable zkEVM, they make the ecosystem more attractive to all other participants. For example:
- More users will already have Passport wallets and can instantly onboard into your game
- More marketplaces will join our Marketplace Network and support Immutable zkEVM assets
- More game-specific tooling will be built for the ecosystem (e.g. data analytics)
- More composability will be possible between games, allowing for innovative economy mechanics and exciting marketing campaigns
- More liquidity will have formed in DeFi tools on the chain
- More gamers will already have funds on the chain and be purchase-ready
- More games will exist as proof points and demonstration examples
- More VCs will have existing investments in zkEVM games, and therefore an incentive to fund other games and tools
This “snowball effect” should make it clear that the choice of a chain and ecosystem is crucial. In the first 5 years of blockchain gaming, games commonly chose a blockchain based on grants or marketing hype. Unfortunately, if these blockchains subsequently failed to build ecosystem traction or create compelling platform tools, the growth potential of those games has been massively limited.
Developers who build on Immutable and Ethereum can expect to continually benefit from the gravity of the Immutable ecosystem. Not all games which build on Immutable will be successful, but building with us will give your game the best possible launchpad towards long-term growth and sustainability.
Building your game on Immutable zkEVM
Building on Immutable zkEVM will give developers not just a purpose-built gaming blockchain and world-class platform toolset, but also the confidence of building as part of the largest ecosystem in web3 games.
Our goal is simple: mainstream-quality games with blockchain asset ownership.
If that’s your goal too, build your game on Immutable.
About the author
Alex Connolly is Co-Founder & CTO at Immutable. Follow on Twitter