Robinhood Chain is a permissionless Ethereum L2 on the Arbitrum stack, chain ID 4663, live since 1 July 2026. Here are the verified specs, the real constraints, and the case for building a game on it.
By Proud Lion Studios · 20 September 2026 · 8 min read
Most explanations of Robinhood Chain get the single most important fact wrong, in the direction that flatters everyone building on it. So we will lead with the correction: Robinhood Chain is a public blockchain that is not connected to your Robinhood brokerage account, and deploying a contract on it gives you no access whatsoever to Robinhood's customers.
Everything below is sourced. Where we measured something ourselves, we say so.
Robinhood Chain is an Ethereum Layer 2 built on the Arbitrum stack. Its public testnet opened on 10 February 2026 and mainnet went live on 1 July 2026, announced at a Robinhood keynote in London. It is an optimistic rollup publishing its data to Ethereum, and it uses ETH for gas, so there is no separate network token to acquire.
The network parameters:
0x1237
https://rpc.mainnet.chain.robinhood.com
robinhoodchain.blockscout.com
We confirmed the chain ID and RPC by direct probe on 20 September 2026: eth_chainId returns 0x1237, and the chain was at block 68,017,296.
eth_chainId
Deployment is permissionless. Robinhood's support documentation says anyone can interact with the network, build applications and deploy smart contracts, and we verified it independently: a contract creation estimated from an unfunded, unknown address returns a normal gas estimate rather than an allowlist rejection. No partner gate, no KYC, no application form.
No, and this is the claim to be careful about.
Robinhood's support article states that the chain operates independently of the main Robinhood app and does not affect your investments, crypto balances or portfolio. It is offered through a separate legal entity, and Robinhood's chain page carries an explicit disclaimer: not provided by Robinhood UK Ltd, not authorised or regulated by the UK Financial Conduct Authority, conferring no UK financial services regulatory protections.
For builders the practical translation is blunt: shipping on Robinhood Chain is not an endorsement, a partnership, or a distribution deal. It is the same relationship you have with Base or Arbitrum One. Any project implying otherwise is making a claim that the chain's own documentation contradicts.
This is where the honest answer is less comfortable than the marketing.
L2BEAT classifies Robinhood Chain as a Stage 0 rollup. A single sequencer, operated by Robinhood, orders every transaction. Fraud proofs are deployed, using Arbitrum's BoLD dispute system, but the validator set is whitelisted: only two approved actors can propose or challenge a state root, and the challenge period runs about six days and eight hours. Contracts are instantly upgradeable by a 7-of-8 Security Council multisig with no delay, so there is no exit window if an upgrade goes against you. ArbOS also lets an authorised filterer force specific transaction hashes to fail, even ones force-included from Ethereum.
None of this is unusual for a young L2, and Arbitrum One itself started in a comparable place. But if your pitch involves the word "decentralised", the chain will not currently support it.
Cheap, with an important caveat about which number you quote.
The chain enforces a gas price floor of 0.02 gwei. At that floor, with ETH near $2,580, a simple transfer of 21,000 gas costs roughly $0.001, about a tenth of a cent. That is the number most articles cite, and it is not the number you will usually pay. When we queried eth_gasPrice on 20 September 2026 the chain returned 0.056 gwei, roughly 2.8 times the floor, putting a simple transfer near $0.003 and a typical ERC-721 mint of about 120,000 gas near $0.017. Gas has been volatile: reporting in early September recorded a median base fee more than twenty times the floor during a memecoin surge.
eth_gasPrice
So the accurate framing is a range: a game interaction costs between a tenth of a cent and a few cents depending on congestion. That is cheap enough to put game logic on chain, which is the only thing that matters, and it is worth designing for the upper end rather than the floor.
One correction that matters, because it is widely repeated: the 90-day gas subsidy that ran from 1 July to roughly 29 September 2026 covered swap costs inside the Robinhood Wallet app. Third-party wallets paid standard gas throughout, and the subsidy never covered dapp interactions such as NFT mints. Nobody minted anything for free because of it.
Large on the financial side, thin on the NFT side, and cooling from a speculative peak.
As of 3 September 2026, DefiLlama showed roughly $791 million of chain TVL, $2.78 billion of bridged TVL and $868 million of stablecoins, on cumulative totals since launch of about $34.6 billion of DEX volume, 576 million transactions and 12.3 million addresses.
Those numbers need two asterisks. Concentration: Uniswap accounted for 85.8% of 30-day DEX volume, and much of the consumer activity ran through a single memecoin launchpad rather than the tokenised equities the chain was pitched on. Trend: by 14 September 2026, daily chain revenue had fallen to about $436,000, down more than 90% from a peak above $5.4 million, with DEX volume roughly halved.
NFTs are smaller again. OpenSea added Robinhood Chain support in July 2026 with full marketplace tooling. Activity spiked in August, one day exceeding $1 million in volume. But CoinGecko currently tracks 84 NFT collections on the chain, combined market cap near $48.9 million, 24-hour volume roughly $233,000. A real market, and a small one.
The tooling story is better than the ecosystem story, which is the usual shape of an opportunity.
The EVM is Cancun-level, so Solidity, Hardhat, Foundry, viem and wagmi run unmodified. We verified by direct eth_getCode probe that the canonical ERC-6551 registry and the ERC-4337 EntryPoint v0.7 are both deployed at their standard addresses, so token-bound accounts, sponsored gas and session keys all work. Multicall3 is present. Chainlink went live from block zero with CCIP, Data Feeds and Data Streams.
eth_getCode
Three traps worth knowing before you write a line:
blockhash
block.number
0x6F475642a6e85809B1c36Fa62763669b1b48DD5B
Start with the reasons not to, because they are real.
There is no built-in distribution. Robinhood's chain page has no gaming or NFT category, and the chain is not a funnel to Robinhood's user base. Any audience a game has here is an audience it imported itself. NFT volume is thin. The chain is Stage 0 with a single sequencer. And cloning is rampant: cheap gas makes copycat collections nearly free to deploy, and we have had a fake Ethernal Cubs collection listed and later delisted. Budget for that rather than be surprised by it.
The case for building there anyway comes down to four things.
Cost per interaction. A game that settles equipment changes, battles and item transfers on chain does a lot of transactions. At a few cents each, that is a product. At Ethereum mainnet prices, it is not.
Composability primitives that are actually deployed. ERC-6551 means an NFT can hold other NFTs. For a game where a character is assembled from separate part tokens, that is not a nice-to-have, it is the architecture.
A marketplace on day one. OpenSea support means a project does not have to bootstrap its own secondary market, which is where most game economies quietly die.
Reversibility. The underrated one. Because the bytecode is portable, this is not a bet you cannot unwind: if the chain stalls, the fallback is a redeploy to Base or Arbitrum One, not a rewrite. Early-ecosystem risk is genuinely capped.
The honest summary: Robinhood Chain is a good place to build a game and a bad place to expect an audience to arrive on its own. Those two facts are compatible, and confusing them is how projects get hurt.
Ethernal Cubs is a game franchise, not a profile-picture drop, and among the first of its kind on this chain. The collection contract is at 0x39c7CaC949BeEb899a412ac9f5e53a48d209acDa, supply 3,333 Orbs. We read both figures off the chain rather than from a press page.
0x39c7CaC949BeEb899a412ac9f5e53a48d209acDa
The design leans on exactly the primitives described above. A Cub is assembled from eight slots drawn from 155 trait artworks, which multiply out to more than 13 billion possible combinations, and because every part is its own token, parts re-equip at any time. A Cub is never locked into the way it minted. On top of that sit an AI companion layer, an autonomous battle arena where rarity feeds combat power, and a prize and giveaway programme. Access to the mint is by whitelist.
That is a product shaped around cheap on-chain state changes and token composability, which is the specific thing this chain is good at, and it does not depend on the chain handing it an audience.
The collection is on OpenSea at opensea.io/collection/ethernal-cubs-orbs. Resolve it from the contract address above rather than by name, because impersonators exist.
Chain ID, gas price, block height, the ERC-6551 and ERC-4337 deployments, the LayerZero endpoint address and the Ethernal Cubs contract supply were verified by direct JSON-RPC calls to https://rpc.mainnet.chain.robinhood.com on 20 September 2026.
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