Litepaper

1. Summary

Players own rigs (NFTs), drill wells, manage well pressure, refine crude and gas into six energy products, sell them for in-game coins and export them for XOM. Each product's price follows a real benchmark through Chainlink price feeds. A fixed share of project revenue buys XOM, the Exxon Mobil stock token on Robinhood Chain, and holds it in a reward vault that pays out what each rig exports.

2. Why this game

Robinhood Chain was built for tokenized real-world assets and gives every stock token a Chainlink price feed. Most chain games pay players in their own token. Barrel Royale pays its headline reward in an asset that has value well beyond the game, funded by revenue, and makes the game itself worth playing first.

3. Game design

The core loop is drill, manage pressure, refine, sell or export, defend and upgrade. Section 11 lists which parts are live in the browser game today.

• Wells and pressure: three raw products; a choke trades output against blowout risk.
• Refinery: distillation, cracker and liquefier turn crude and gas into diesel, jet fuel and LNG.
• Selling: the spot market at the index, or Dispatch contracts at a fixed premium price, both paid in in-game coins.
• Export: barrels shipped through the export terminal turn into XOM, up to a daily quota per rig.
• Incidents: storms with an active brace phase; sabotage as raids between crews.
• Crews and seasons: 20-rig crews, shared projects, raids and a season prize pool.
• Shifts: a daily budget of active moves that keeps play fair between players and scripts.
• Free players: a starter platform, plus shifts on other players' rigs that pay both sides.

4. Energy price index

For each product, the index is the benchmark price now divided by its reference at the start of the season, held within a steady band.

The game server reads Chainlink feeds on Robinhood Chain through the standard AggregatorV3Interface; benchmarks without a feed follow a simulated index until one is available. Following Robinhood's guidance, the server:

• checks the L2 sequencer uptime feed and waits out a grace period after any outage;
• only accepts fresh prices, comparing updatedAt with the feed heartbeat;
• reads decimals() from each feed and rejects zero or negative values.

Dispatch contracts pay a fixed price, so players who prefer building to market-watching always have a steady way to earn.

5. Economy

$ROYAL

$ROYAL is a fixed-supply ERC-20 with a fair launch: no presale and no private round. It is spent on rig class upgrades and cosmetics, which burn it, and a share of revenue buys it back and burns it too. In-game sales pay coins, which never leave the game. Barrels become XOM only through the export terminal, up to a daily quota per rig.

Rig class upgrades

The RigUpgrader contract raises a rig's class by burning $ROYAL. Costs count from Jack-up, so a holder pays only the difference, and the contract has no owner.

Rig mint

6. XOM rewards

XOM is an ERC-20 stock token on Robinhood Chain that tracks Exxon Mobil. The treasury buys it carefully so every purchase gets a fair price:

• small batches spread across the week;
• a 1% slippage limit on every trade;
• every purchase listed in the public treasury log.

Each rig's exports are tallied every week and priced in XOM through the Chainlink feed. The vault records each week's Merkle root of rewards and holders claim with a proof. The rate and the daily quota keep weekly exports well inside what the vault receives from revenue, and both can change only through the timelock in section 7.

7. The reward vault

The XOMRewardVault keeps two balances apart. XOM owed to players, from every posted week that is not yet claimed, can only leave through their claims. The free balance, XOM the treasury bought that no player has earned yet, is managed by the treasury multisig under fixed limits:

• every withdrawal is scheduled on-chain and executes only after a 7-day timelock;
• at most 20% of the free balance can leave in any 30 days;
• withdrawals move funds to a new vault version or rebalance the treasury, each listed in the monthly report;
• changes to the export rate and quota use the same timelock;
• claims can be paused for at most 14 days for a security issue, and paused time is added to every claim window;
• one round per week, at least 6 days apart and at most 10% of the free balance, with claims opening 2 days after posting;
• unclaimed rewards return to the free balance after 12 weeks.

8. Fair play

A reward with real value deserves real players. Barrel Royale is built for that from day one:

• The game server decides every outcome; the client only sends what the player wants to do.
• Shifts set a daily budget of active play per rig, and exports stop at a daily quota.
• Exports count only from rigs that show varied, active play: shifts, contracts and storms.
• Rate limits, one session per account, and a quick check at sign-up and at claim time.
• Rigs flagged for review are held back from that week's Merkle root until they are cleared.

9. Architecture

• RoyalToken: ERC-20 with a fixed supply and no owner after launch: no minting, pausing or blacklisting.
• RigNFT: ERC-721 with commit-reveal class assignment.
• RigUpgrader: burns $ROYAL to raise a rig's class, with fixed costs and no owner.
• XOMRewardVault: holds XOM, stores weekly Merkle roots, pays claims, keeps player rewards apart from the timelocked free balance, and stores the export rate and quota.
• Game server: wells, refinery, contracts, incidents and crews, plus an indexer that tallies each rig's exports for the week and builds the Merkle tree.

10. Safety and transparency

• OpenZeppelin contracts with reentrancy guards and an emergency pause.
• Every admin role and the treasury held by a multisig, so no single key can move funds.
• A 7-day timelock on vault withdrawals and on changes to the export rules, so every admin action is public before it applies.
• Automated tests for every vault limit, published with the contract source.
• Source code verified on the Robinhood Chain explorer for every contract.
• A monthly treasury report linking every XOM purchase and every $ROYAL burn.
• Rewards follow revenue and play, and every number is public.

11. Status

12. Sources

• Robinhood Chain: Oracles and price feeds
• Robinhood Chain: Stock tokens
• rwa.xyz: Exxon Mobil on Robinhood Chain