Immutable announces transition to Ethereum Rollup: migrating to OP Stack in 2027, reducing block time to 1 second

Immutable said it will migrate Immutable Chain from its custom Geth fork to an OP Stack-based architecture in mid-2027, converting the gaming chain into a standard Ethereum rollup with 1-second block times, down from 2 seconds. The move replaces its Axelar-based cross-chain messaging with Ethereum-native state commitments, starting with permissioned fault proofs and later adding ZK validity proofs, and brings Immutable into the Optimism Superchain ecosystem. The migration will preserve Chain IDs, user addresses, token balances and contract logic without manual asset transfers, though mainnet block production will pause for several hours during the cutover. The trade-off is higher base transaction costs from posting data to Ethereum's DA layer and a roughly 7-day withdrawal challenge window on the native bridge, with external liquidity providers needed for instant exits. Immutable will also wind down testnet support for game projects by the end of 2026. Watch for the published cutover schedule and the phased rollout of fault proofs as the chain shifts its security and bridging model to Ethereum settlement.