Frequently Asked Questions
General
What is merca.earth?
merca.earth is a world map where you can claim any place, name it, design how it looks, and own it — until someone pays more to take it. Draw a shape anywhere on Earth, register it on the Sui blockchain, and control the visual layer: title, artwork, description. Every place is always up for grabs, so the map shows what people care about enough to compete for. See Key Concepts for the full picture.
What blockchain does merca.earth use?
merca.earth runs on Sui, a high-throughput Layer 1 blockchain. All parcels, ownership records, and transactions live on Sui. Payments are denominated in SUI (the native token). See Getting Started for what you need before your first registration.
Do I need crypto experience to use merca.earth?
No. Sign in with Google — no wallet extension, no seed phrase, no prior blockchain knowledge. The app creates a Sui wallet behind the scenes using zkLogin. If you already have a Sui wallet, you can connect that instead. See Connecting a Wallet.
Wallet & Access
What wallets does merca.earth support?
Three options: social sign-in (via zkLogin), Sui browser-extension wallets (Slush, OKX Wallet, Suiet, Martian, Surf, Nightly, and others), and MetaMask with the Sui Snap on desktop. Social sign-in providers depend on how the app is deployed: Enoki-backed deployments support Google, Facebook, and Twitch; self-hosted zkLogin deployments support Google only. The app detects installed extensions automatically. See Connecting a Wallet for step-by-step instructions.
Can I use a social login instead of a crypto wallet?
Yes. Click the wallet button, choose Enoki Sign-In, and authenticate with Google, Facebook, or Twitch. A Sui wallet is created behind the scenes — nothing to install, no seed phrase to store. This is the recommended path for newcomers. See Connecting a Wallet.
What is zkLogin?
zkLogin is a Sui protocol feature that derives a blockchain address from your social identity using zero-knowledge proofs. Your social credentials never touch the chain — the proof confirms you control the account without revealing private data. The result is a real Sui wallet tied to your social account. Which providers are available (Google, Facebook, Twitch) depends on the deployment. See Connecting a Wallet for how the flow works.
Land Registration
How do I register a parcel?
Open the app, click Draw New Parcel, place vertices on the map to define your shape, then click Complete. The app shows a preview with area, price, and hierarchy level. Click Register, approve the transaction in your wallet, and the parcel is yours on-chain. Full walkthrough: Registering a Parcel.
Why was my registration rejected?
The protocol enforces strict geometry rules. Common reasons for failure: the shape overlaps an existing parcel, the area falls outside the level's min/max bounds, edges are too short, the shape is too thin (fails the compactness check), or the shape can't be decomposed into 10 or fewer convex parts. The app highlights the problem before you submit. See Geometry Rules → Troubleshooting for the full validation rules.
Can two parcels overlap?
No. The protocol checks every registration against existing parcels using the Separating Axis Theorem. If your shape overlaps anything already on-chain, the transaction reverts and nothing is recorded. The app flags conflicts in real time while you draw. See Key Concepts for how the spatial index works.
What is the minimum size for a parcel?
Each hierarchy level sets its own minimum and maximum area bounds. The app shows the allowed range in the sidebar while you draw. Shapes outside those bounds are rejected at submission. See Pricing for how area bounds relate to cost, and Geometry Rules for all validation constraints.
Buying & Pricing
Can an owner refuse to sell?
No. Every place is always for sale. Pay the current price and you're the new owner — instantly, automatically. The previous owner gets 85% of the payment. There is no "not for sale" option, no delisting, no way to block a purchase. See Buyout & Premium → Every Parcel Is Always for Sale.
How is the buyout price calculated?
The buyout price is area × base rate × premium multiplier. Registration itself is charged at a 1.0× premium, but the stored on-chain premium advances immediately, so a freshly registered parcel's next buyout already uses roughly 2.95×. Each later sale escalates further according to the resale ladder, tapering toward 1.15× per sale after the 64th. See Pricing and Buyout & Premium for the full formula.
What happens to the previous owner when I buy their parcel?
They receive 85% of the buyout price as a direct SUI transfer in the same transaction — no separate claim needed. The remaining 15% splits between the protocol treasury (7%) and the hierarchy pool (8%). See Buying a Parcel.
Why does the price increase after each sale?
Because the map should reflect what people actually care about. Places nobody wants stay cheap. Places people fight over get expensive — a place sold five times costs ~35x its registration price. This discourages squatting and rewards early claims in valuable areas. See Buyout & Premium for the full resale ladder.
Can I raise or lower my parcel's price myself?
Yes. The detail panel for your parcel has two buttons: Bump Price and Drop Price.
Bump Price raises your price by one step on the resale ladder. It costs 15% of the current buyout price (7% to the protocol treasury, 8% to the hierarchy pool). Use it to make your parcel more expensive to take.
Drop Price lowers your price by one step. It costs 8% of the current buyout price (hierarchy pool only). You can drop all the way back to the original registration base price — there's no floor above what you first paid. Use it to attract a buyer or reduce your exposure.
Both operations are irreversible and take effect immediately. See Territory Operations → Bump / Drop and Pricing → Owner Price Controls for full details.
Economics & Cash Flows
How do I earn money?
Two ways. Resale: when someone buys your place, you get 85% of the sale price automatically — it arrives in your wallet in the same transaction. Tax: if you own a large territory (say, a country-level claim), you collect 8% of every transaction from smaller places inside it. Tax requires periodic collection before buckets expire. See Cash Flows.
What is the 8% hierarchy pool?
Every payment on merca.earth — registration, buyout, expansion, slice acquisition — routes 8% into the hierarchy pool. That 8% flows upward through the spatial hierarchy as tax revenue for parent parcel owners. The direct parent keeps half; the remainder cascades further up the tree, split equally among remaining ancestors. See Fees and Tax for how the split works.
What happens if I don't collect my tax revenue?
You lose it. Tax sits in time-limited buckets, not in your wallet. If you don't collect before the expiry epoch, anyone can sweep the funds to the protocol treasury — permanently. No grace period, no recovery. Check and collect regularly. See Tax → Bucket Expiry.
Technical
What is the visual layer?
The visual layer is how your place looks on the map: its name, description, and artwork. You control all of it. Upload images, draw on it, write a description in markdown — visitors see what you designed when they click your place. Only the current owner can edit it, and updates cost only gas. See Name & Visual Layer.
Where is parcel artwork stored?
Visual content (sketches, images, the structured document) is stored on Walrus, a decentralized storage network. The Sui blockchain holds only a lightweight URI pointing to that content. This keeps on-chain costs low while keeping your content censorship-resistant and verifiable. See Name & Visual Layer.
What is the quadtree hierarchy?
The world map is recursively divided into quadrants — each quadrant splits into four smaller ones, up to 20 levels deep. Every parcel lives at the shallowest level where its bounding box fits inside a single cell. This hierarchy determines which parcels are "parents" of others and drives the tax cascade: parent parcels earn revenue from economic activity inside their boundaries. See Key Concepts → Spatial Hierarchy and Hierarchy → Six Hierarchy Levels for the full technical details.
Paint
Do I need a wallet to paint?
No. Paint is the only thing on merca.earth that does not require a wallet. Open the map, click the paint button, pass a quick bot check, and start drawing. No sign-in, no gas, no fee. See Paint → Starting a session.
What is ink?
Ink is your per-session paint budget. Each level — continent, country, region, city, district, block — has its own allocation, calibrated so one full session covers a comparable share of your viewport at any zoom. Block sessions get the most ink (16,000 units), continent sessions get the least (500). When ink runs out, a twenty-minute cooldown begins on that level. Other levels stay open. See Paint → Ink and Cooldown.
Why can I not paint over my neighbor's parcel?
Registered parcels block paint. Every commit is checked against current parcel boundaries, and pixels covered by an existing parcel are dropped before they reach the canvas. The owner sees their visual layer; the painter sees their strokes flow around the boundary. See Paint → Painting around parcels.
What happens to paint when someone registers the land underneath?
The paint inside the new parcel boundary is cropped and pre-filled into the parcel's visual layer editor as a starting image. The public canvas loses those pixels — they belong to the new owner now, who can keep them, edit them, or replace them entirely. The rest of the public canvas, outside the new boundary, is untouched. See Paint → From paint to ownership.
Why are there colored dots on the map at low zoom?
Those are activity dots. They mark where painting is happening at a finer level when you are zoomed too far out to see the pixels themselves. Size scales with the seven-day commit count; color shows recency — red for the last hour, orange around a day, gray near the end of the week. Zoom in toward a bright dot and the paint appears. See Paint → Activity Dots.
Is paint moderated?
No. The constraints are mechanical only: a bot check blocks automated abuse, ink budgets cap session output, the occupied mask protects parcels. There is no automated content filter and no human review. If something objectionable appears, the response paths are: register the land underneath (which absorbs the paint into your visual layer, off the public canvas), or report it to the team for manual takedown.
Can I undo a paint stroke after I save?
Inside a session, yes — Cmd+Z or Ctrl+Z reverts your last stroke. Once the session closes, the strokes you committed stay. There is no cross-session undo. The public canvas is collaborative; once your pixels are visible to others, they need to be erased like anyone else's, which spends ink at that level.
See also: Key Concepts → Spatial Hierarchy · Getting Started · Glossary · Wallet Setup → Connection Methods