Layer 2 blockchain list: scaling architectures powering modern Web3 games

A game action is signed. A sequencer orders it. An execution environment changes state. Data is published somewhere. A proof or challenge mechanism reaches Ethereum. The asset becomes withdrawable only under the rules of that bridge. Every missing step is a trust assumption.

For Web3 games, this distinction is not academic. A marketplace can tolerate delayed settlement. A turn-based strategy game can tolerate asynchronous messages. A real-time combat loop cannot wait for Layer 1, and it should not pretend otherwise. The viable architecture is usually hybrid: a conventional backend handles the dense simulation; an execution layer settles scarce assets, rewards, crafting outcomes, and transfer rights.

This is the actual gaming rollups comparison. Not “which chain is fastest.” Speed claims without a finality definition are marketing inventory.

A sequencer confirmation is not Ethereum settlement. A cheap transaction is not necessarily a cheap exit.

The baseline: what belongs on a Layer 2 list

Ethereum defines rollups as systems that execute transactions outside Layer 1 while posting transaction data to Layer 1 for consensus. That broad definition still leaves a structural split.

Optimistic rollups assume state proposals are valid unless challenged. Their security model depends on a challenge process, fault-proof machinery, and the availability of sufficient data for a challenger to reconstruct and dispute fraudulent execution.

Validity rollups, commonly called ZK-rollups, submit cryptographic proofs that attest to valid state transitions. Ethereum verifies the proof before the associated state is finalized. This changes the withdrawal model and verification path, but it does not eliminate operational questions around sequencers, upgrade controls, proof systems, bridges, and data availability.

A validium is not interchangeable with a ZK-rollup. Both may use validity proofs. The difference is where transaction data lives. A rollup posts it to Ethereum. A validium keeps it elsewhere. That distinction is easy to omit in a gaming blockchain directory because the user interface may look identical. The recovery assumptions are not identical.

The following list is therefore architectural rather than exhaustive. There is no single official registry of Ethereum Layer 2 networks, and no permanent classification survives every protocol upgrade. The relevant question for a game team is narrower: what exactly is secured on Ethereum, what remains off-chain, and what fails when an operator stops cooperating?

This is not a ranking. It is a map of trade-offs. A studio selecting one of these web3 execution layers is choosing a failure model as much as an API.

Optimistic systems: efficient execution, delayed escape hatch

The OP Stack is relevant to games because it standardizes a widely copied route into Ethereum-connected execution. Teams can deploy Solidity contracts, reuse EVM tooling, and avoid building a bespoke validator set or execution environment from scratch. That lowers integration friction. It does not make the resulting application decentralized by default.

The key mechanic is the dispute window. Optimistic systems accept state proposals provisionally. A fault-proof process exists so that invalid proposals can be challenged. Optimism activated fault proofs on OP Mainnet on June 10, 2024, and its documentation describes an approximately one-week challenge period for optimistic-rollup proposals.

That interval is usually invisible during ordinary gameplay. A player clicks a marketplace listing, the sequencer accepts the transaction, and the application can show a result. But the ordinary path is not the same as withdrawal finality. The distinction becomes material when a player needs to move assets back to Ethereum under adversarial conditions.

Base illustrates the separation cleanly. Regular Layer 2 transactions do not carry a seven-day delay. Withdrawals from Base to Ethereum do. The seven-day finalization period exists so fault proofs can challenge a malicious state proposal. Base documentation also describes Layer 1 batch finality at approximately 20 minutes after two Ethereum epochs, or 64 Layer 1 blocks. Neither figure means that every player-facing action has final settlement in twenty minutes. The withdrawal path still has its own clock.

For games, this produces a simple design rule: do not build a core player promise around immediate canonical exits from an optimistic rollup. If players can trade in-game assets internally, fine. If they need immediate redemption on Ethereum in the same product flow, the bridge mechanics will contradict the interface.

Arbitrum Nitro occupies the same broad family: an optimistic-rollup architecture anchored to Ethereum. Nitro has been deployed on Arbitrum One since August 31, 2022. Its AnyTrust variant is a useful warning against category errors. It can reduce costs, but it introduces an additional trust assumption. Lower operating cost is not a free parameter. Somebody is now responsible for data availability under conditions that differ from a conventional rollup.

A studio should separate three questions that are commonly collapsed into one:

1. Can the game execute cheaply during normal operation? This concerns gas markets, block capacity, sequencer behavior, batching, and contract design.

2. Can a player recover assets if the normal operator path fails? This concerns bridge contracts, posted data, fault proofs, and the exact withdrawal procedure.

3. Can the game continue functioning while recovery is happening? Usually, only if the critical game state is not entirely dependent on the chain.

The third question is where many scaling solutions for Web3 gaming become less impressive. A chain can settle ownership. It cannot automatically replace matchmaking, anti-cheat telemetry, simulation servers, or a live-ops database.

ZK-rollups: proof-based settlement does not erase latency

ZKsync Era takes a validity-rollup route. Its architecture includes a sequencer that orders and executes transactions, a Boojum prover that generates validity proofs for batches, and an Ethereum verifier contract that checks those proofs and finalizes state transitions.

This offers a cleaner finality story than an optimistic system’s challenge window. The chain does not merely wait to see whether someone objects; it presents a cryptographic validity proof for the batch. But “proof-based” should not be translated into “instant” or “trustless in every component.”

A player’s experience still depends on the sequencer’s response time, the timing of proof generation, batch submission, Ethereum inclusion, and the application’s own decision about what confirmation it considers usable. A sequencer can provide a rapid local confirmation. That is useful for interface responsiveness. It is not equivalent to finalized Ethereum state.

ZKsync Era is particularly relevant to consumer-facing games for its account model. The network documents native account abstraction, ERC-20 fee payments, and paymasters. Those features can hide the usual wallet friction: a player may not need to acquire the network’s native gas asset before performing a first action, and a publisher can sponsor eligible transactions.

That is a product capability, not a protocol guarantee. Sponsorship has a payer. It has eligibility rules. It can be rate-limited. It can be withdrawn when the game’s unit economics change. A game team that treats sponsored gas as a permanent infrastructure constant is designing against its own budget.

ZKsync Era also supports existing Solidity and Vyper contracts with minimal or no changes, despite its EraVM execution environment. This reduces porting work for EVM-native teams. It does not eliminate the need to test compiler behavior, account abstraction flows, signature handling, indexers, bridge contracts, and the full wallet path. “Compatible” is an engineering starting point, not an audit result.

Starknet is built around a different validity-rollup design, using STARK-based proofs. Its most important game-design constraint is not the proof branding. It is asynchronous Layer 1-to-Layer 2 and Layer 2-to-Layer 1 messaging.

A Starknet contract cannot send a cross-layer message and wait for the result during the same execution. That rules out a class of simplistic designs in which game logic expects a synchronous callback from Ethereum. A crafting system that burns an L1 asset and immediately mints a corresponding L2 item must be designed as a multi-step state machine. So must any withdrawal-triggered reward, cross-chain tournament payout, or bridge-dependent inventory update.

Starknet’s documented L2-to-L1 message fee model also demonstrates why “cheap L2” is incomplete language. Sending such a message carries a fixed cost of 20,000 L1 gas, with the documentation using a conversion of one L1 gas to 40,000 L2 gas for the described model. The exact monetary result varies with network conditions. The architectural point does not: crossing the boundary remains expensive relative to staying inside one execution domain.

Rollups reduce the cost of repeated state changes. They do not repeal the cost of crossing trust domains.

Immutable Chain: gaming tooling is useful, but tooling is not the trust model

Immutable Chain is one of the clearer examples of a gaming-focused execution environment because its published stack addresses the practical systems around contracts rather than stopping at block production.

The mainnet uses chain ID 13371. The testnet uses 13473. Documentation lists an approximately two-second block time and approximately two-second finality, EIP-1559 gas pricing, and a 30,000,000 block gas limit. It also provides TypeScript, Unity, and Unreal SDK options. These details matter because game integration failures often occur outside the solidity contract itself: mobile wallet handoff, inventory indexing, session authorization, transaction status, and engine-side handling of failed writes.

For a Unity or Unreal team, an SDK can reduce the amount of custom plumbing required to connect user identities, asset inventories, and transaction prompts. It does not answer the harder question: which state transitions should be transactions at all?

A usable split normally looks like this:

• On-chain: asset issuance, transfer rights, crafting outputs with economic value, tournament prizes, guild treasury movements, and externally verifiable reward claims.
• Off-chain: frame-by-frame movement, hit detection, matchmaking, AI simulation, anti-cheat signals, session state, and rapidly changing telemetry.
• Hybrid: ranked-match results, quest completion, and crafting inputs. The backend calculates the event; the chain settles the result under predefined rules.

This separation is not a compromise with Web3 principles. It is throughput discipline. A combat game may generate dozens of state changes per second per player. Recording that loop on a shared execution layer creates latency, gas exposure, ordering disputes, and a denial-of-service surface without producing meaningful player ownership.

Immutable Chain also lists gas sponsorship for Passport users. That can remove a visible barrier at onboarding. A first-time player does not need a network-specific balance before accepting a starter item or making an inventory move. But teams should model this as an operating expense and abuse target. A faucet-like sponsorship path invites automated account creation, low-value transaction spam, and extraction attempts if issuance rules are weak.

The relevant metric is not “gasless transactions.” It is sponsored transactions per legitimate retained player, adjusted for fraud loss and the cost of recovery when a wallet or account link is compromised.

ERC-721 and ERC-1155: the contract shape determines the bill

The asset standard is often treated as a visual choice: unique collectible versus stackable inventory. It is an execution-cost decision.

ERC-721 standardizes ownership and transfer for non-fungible tokens. It fits items whose identity matters individually: a named character, a land parcel, a tournament trophy, or an item with a unique provenance trail. ERC-721 was created in January 2018 and remains the default mental model for NFTs, partly because it is easy to explain.

ERC-1155, created in June 2018, is usually more structurally appropriate for game inventories. A single contract can represent multiple token types: fungible resources, semi-fungible tickets, and non-fungible equipment. It also supports batch transfers. When more than one token type moves in the same operation, batching can reduce gas use relative to multiple separate transactions.

That reduction is not merely an optimization for a busy marketplace. It changes what a game can settle economically. A player claiming five material types, a cosmetic badge, and a quest key should not require seven independent settlement paths if the game’s data model does not require them.

There is a corollary. ERC-1155 does not solve poor game economy design. A batch mint can still be exploited. An item contract can still expose unsafe authorization. Metadata can still disappear if decentralized storage is not pinned and maintained. The standard defines token interfaces, not the integrity of the game issuing them.

Smart-contract audits do not close this gap automatically. An audit has a scope, a date, assumptions, and findings. Contracts change after audits. Dependencies change. Upgrade authorities may change the effective logic without a player ever touching the original contract address. For an asset layer carrying real value, the operational question is always: who can alter the rules, pause transfers, or redirect bridge behavior?

The bottleneck is rarely the chain alone

The recurring mistake in layer 2 networks for games is to select infrastructure as if the game were a single smart contract. It is not. It is a system spanning an engine client, account layer, wallet integration, backend services, transaction relayers, indexers, asset storage, marketplace logic, bridge contracts, and support operations.

Each component introduces a different kind of friction.

Wallet integration introduces signature friction. Gas sponsorship introduces budget and abuse friction. Cross-chain bridges introduce finality friction. Indexers introduce data-consistency friction. Sequencers introduce ordering and liveness friction. Upgrade keys introduce governance friction.

A chain with two-second blocks does not remove any of these layers. It may make the normal transaction path feel responsive. That is useful. But the game must still define what happens when an indexer falls behind, a wallet rejects a signature, a sequencer stalls, a sponsored transaction is denied, or an asset withdrawal enters its finalization period.

The strongest architecture is usually the least theatrical one. It keeps the high-frequency game loop outside the chain. It puts only economically meaningful, auditable transitions into the rollup. It uses account abstraction and sponsorship where they reduce player friction without obscuring cost. It treats bridges as separate systems with separate risk budgets. And it exposes settlement status honestly instead of calling every green UI checkmark “final.”

Verdict: scalable for settlement, not for the game loop

The layer 2 blockchain list is useful only when read as a set of constrained execution architectures.

Optimistic rollups such as OP Stack deployments and Base offer familiar EVM paths, but their Ethereum withdrawal mechanics impose a challenge-window reality. Arbitrum Nitro adds another mature optimistic design, while AnyTrust-style cost reductions must be recognized as extra assumptions rather than free throughput. ZKsync Era and Starknet use validity proofs, yet their sequencing, proof-generation, and cross-layer messaging models still shape application latency and recovery. Immutable Chain reduces integration friction with gaming SDKs and sponsorship paths, but its tooling does not substitute for system design.

Binary verdict: Layer 2 infrastructure scales ownership settlement, asset transfers, and infrequent economic state transitions. It does not scale a real-time game loop merely by being called a gaming chain.

Teams that respect that boundary can build workable systems. Teams that put combat, movement, and every inventory tick on-chain are not decentralizing gameplay. They are importing avoidable latency into it.