A Layer 2 (L2) is a scaling solution built on top of a base blockchain (“Layer 1” or L1 — most commonly Ethereum) that processes transactions off the main chain while inheriting L1’s security guarantees. Layer 2s exist to address the core limitation of major L1s: throughput (transactions per second) and cost (gas fees) cannot scale linearly without compromising decentralization or security.
Two principal Layer 2 architectures dominate Ethereum scaling: optimistic rollups (Arbitrum, Optimism, Base) — which assume transactions are valid by default and rely on a fraud-proof window during which challengers can dispute incorrect state transitions; and zero-knowledge rollups (zkSync, Polygon zkEVM, StarkNet, Scroll) — which use cryptographic validity proofs (SNARKs or STARKs) to prove transaction correctness without revealing transaction details. Other approaches include sidechains (Polygon PoS), state channels (Lightning Network on Bitcoin), and validium architectures.
L2s have become the principal execution environment for Web3 applications: lower gas costs (often 10–100x cheaper than Ethereum mainnet), higher throughput (1,000–10,000 TPS), and inheritance of Ethereum’s security guarantees create the technical preconditions for consumer applications, gaming, social, and high-frequency DeFi protocols.
From a legal perspective, Layer 2 networks raise novel considerations: governance of bridge contracts (the on-chain mechanism connecting L2 to L1), sequencer centralization risk (whether one entity controls transaction ordering), upgradability rights (admin keys that can modify L2 logic), and jurisdictional analysis (where is an L2 “located” for regulatory purposes — where the sequencer operates, where the foundation is incorporated, or where users transact). Sequencer revenue allocation and the eventual transition to decentralized sequencing are emerging governance and tokenomics topics.
Vircon Legal advises Layer 2 projects, infrastructure operators, and DeFi protocols building on L2s on entity structuring, foundation governance, bridge architecture, sequencer revenue arrangements, and the cross-jurisdictional analysis of L2-based commercial activity.