Most "blockchain games" mint an NFT and keep the rules on a studio server. An onchain game puts logic and state in public contracts, so the game can continue even if the website dies.
What is an onchain game?
An onchain game is a game whose logic and state live in public smart contracts. The frontend is optional. Studio servers are not required for the game to continue.
The game is the loop: whose turn it is, what a move does, who won. Payments, receipts, and settlement are not the game. If that loop runs on a private server, you have a Web2 game with a blockchain accessory. If it runs in contracts anyone can read, the chain is the server.
How do onchain games work?
Players submit moves as transactions. The contract checks them against the current state, applies the rules, and writes the new state. Anyone can read the same code and the same save. There is no hidden referee for the parts that actually live onchain.
The official website is a convenience. A second client, or a script, can talk to the same contracts. That is what client-agnostic means. If the studio disappears, those contracts keep executing as long as the chain does.
Fully onchain game vs blockchain game
"Blockchain game" is the baggy public term. "Onchain game" is a narrower claim. Most of what shipped between 2021 and 2024 was the first, sold as the second. Five kinds show up again and again. Only two of them mean the chain runs the game.
NFT wrapper. The game is a normal game. An NFT is a cosmetic, a pass, or a tradable skin. If the studio turns the servers off, you still hold a picture. You do not hold a game.
Hybrid. Ownership lives onchain: the sword, the land, the character. Logic lives offchain: combat, matchmaking, the real rules. This was the default web3 game of the last cycle. You can trade the asset. You cannot reconstruct the match from the chain.
Offchain compute, onchain settlement. A heavy simulation runs elsewhere (a server, a rollup, a proving system). The chain records results, or checks a proof that the results followed the rules. The chain is a court, not the field. This can be rigorous. It is not the game running onchain.
Fully onchain. Logic and state are in contracts. Moves are transactions. This is the strict meaning of an onchain game, sometimes called a fully onchain game or FOCG.
Autonomous worlds. A fully onchain game treated as a world rather than a product: client-agnostic, permissionless to build around, closer to a protocol than a store listing. The studio is a first client, not a landlord.
Wrappers and hybrids put receipts on a chain. Fully onchain games and autonomous worlds put the game on a chain. Settlement-and-proofs sit in the middle, and honest writing should say so.
The NFT survived. The game did not.
The 2021 to 2024 cycle failed this test in public. Studios put items onchain because that was the fundable sentence. They left the game on servers because that was the shippable one. When the token market cooled, live-ops budgets followed. Servers went quiet. Marketplaces did not. You could still transfer the asset. You could not play.
An NFT is a pointer. If its meaning lived in a private database, shutting down the database orphans the pointer. If the rules were never onchain, the chain had nothing to keep alive.
What actually runs onchain in 2026
Latency is the constraint marketing cannot repeal. A public chain, even a fast rollup, is a slow, public computer. Every move is a transaction that has to be ordered, executed, and agreed on. That is a terrible fit for a twitch FPS or a MOBA. Those games need a hidden server that ticks many times a second. Putting that loop in a contract is not a 2026 product.
What does run well: turn-based tactics, cards, slow strategy, persistent simulations measured in hours, not frames. That is the practical onchain vs offchain split. Incomplete information is still hard. The default chain is public, so fog of war is a cryptography problem, not a drawing setting. Zero-knowledge proofs can hide a position while proving a legal move. That has been shown. It is not a platform feature.
If the pleasure is reaction time, keep the simulation offchain. If the pleasure is a rule set that outlives a studio, onchain is the point.
Composability, and the public exploit surface
Because the state is public, anyone can build a client on it. A second map. A bot. A spectator tool. A mechanic the original team never shipped. The rules are a shared object. The table is not owned.
Public logic is a public exploit surface. On a private server, a bad formula can hide until a patch. Onchain, the formula is readable before it is profitable. Bots are not a violation of terms. They are another client. If the contract rewards speed, a script will be faster than you. You are publishing the rules to a hostile, tireless audience.
The chain cannot just roll a die
A chain cannot sample an honest die from inside itself. Naive onchain randomness (a blockhash, a timestamp) is a known footgun. Commit-reveal schemes and verifiable random functions exist to close that hole. They are not interchangeable, and they do not make a game generous. That comparison is VRF vs RNG.
Being able to check a result is not a kind game, a balanced game, or a legal game. That argument is what-provably-fair-means. This page is only the vocabulary those two need. Are the rules on the chain, or only the receipt?
FAQ
Are onchain games fully decentralised?
Usually not. Fully onchain means the game could, in principle, continue without any single party's servers. Frontend, art, metadata, indexer, sometimes the sequencer, often still sit on ordinary infrastructure. Admin keys can still pause or upgrade. Decentralised is a property of each layer.
What is Dark Forest?
History, not a download. Fully onchain space-conquest with ZK so a player could hide a fleet and still prove a legal move. Players built bots and alternative clients against the same contracts. Proof the architecture is possible, not a store listing.
Can the rules be upgraded?
Yes, if the contract was built that way. Upgradeable proxies, admin functions, pause switches are common. Immutable contracts exist too. Honest page: who holds the upgrade key.
What happens if the studio shuts down?
Wrapper/hybrid: token remains, game does not. Fully onchain: contracts keep executing. UI, indexer, art, oracle often die. Permissionless clients are the succession plan.
Are crypto games onchain?
Usually no. If you cannot reconstruct a match from public contracts, it is not an onchain game.
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