Onchain Games: How They Work and What Makes Them Different

An onchain game stores its game logic and state on a blockchain, not just its assets. Most Web3 games use the blockchain as a ledger — tracking who owns what — while the game itself runs on traditional servers. Onchain games go further: the rules of the game live in smart contracts. The game state lives on the chain. The developer’s servers are optional.

This is a distinct category from standard Web3 gaming, and in 2026 it represents a small but growing part of the space.

Standard Web3 games vs onchain games

In a standard Web3 game:

Game logic runs on the studio’s servers
Assets (characters, items, currency) are stored as tokens on a blockchain
Players own their assets onchain but the game itself is centralised

In a fully onchain game:

Game logic is encoded in smart contracts on the blockchain
Game state (every action, every outcome) is written to the chain
No central server is required to run the game
Technically, anyone can build on top of the game’s smart contracts

The distinction matters for permanence and composability. A standard Web3 game with onchain assets still requires the studio’s servers to run. If the studio shuts down, the game stops even if the assets persist. A fully onchain game can run as long as the blockchain runs — permanently, without any central party maintaining it.

What composability means

Because onchain game rules live in public smart contracts, other developers can build on top of them. A third party can create a new interface for an onchain game, add new mechanics, or build entirely new experiences using the same underlying game state.

This is composability — the ability to combine and extend smart contracts the way you combine software libraries. No permission required from the original developer.

The analogy to traditional gaming: imagine if any developer could legally build a new client for World of Warcraft using Blizzard’s game state, with new rules and mechanics layered on top. Onchain games make this possible by design.

The trade-offs

Fully onchain games come with significant trade-offs:

Technical complexity. Writing game logic in smart contracts is harder than server-side code. Every operation has an associated gas cost. Performance is limited by the chain’s throughput.

Cost of play. Every state change in a fully onchain game is a transaction. On chains with significant gas costs, complex interactions become expensive. Optimised chains (Starknet, Optimism, chains with L2 scaling) make this more tractable, but cost remains a design constraint.

Latency. Blockchain confirmation times are slower than server response times. Games that require millisecond reaction times — fast-paced action games, real-time strategy — are not currently viable as fully onchain experiences. Turn-based, strategic, and slower-paced formats translate well.

Attack surface. Game logic in public smart contracts can be examined and exploited. Logic errors that would be invisible on a private server are visible and potentially exploitable onchain. Security audits are not optional.

Games well-suited to the onchain model

Strategy and puzzle games. Turn-based, complex, requiring no real-time response. Chess, Go, complex strategy titles — the format suits the latency profile of current chains.

Card and trading games. Card state is simple to represent onchain. Card battles can be fully onchain. The genre’s existing collector economics translate naturally.

Persistent world simulations. Virtual lands, economies, governance systems. State changes slowly, players act over days and weeks, composability is a feature.

Autonomous worlds. A growing category where the “game” is an open-ended world with basic physical rules encoded in contracts. Players and developers create content inside those rules. Dark Forest is a known early example.

What this means for players

For players in an onchain game:

Permanence. The game’s core state is permanent as long as the blockchain runs. Your progress, your position, your history — all onchain.

Third-party interfaces. Other developers may build alternative interfaces to the game. If you prefer a different UI, you can use it without permission from the original developer.

Transparent rules. The rules of the game are public. A player can read the smart contract and know exactly how the mechanics work. No hidden systems, no unexplained randomness that the studio controls.

Gas costs. Depending on the chain, actions in an onchain game may cost gas. Some games abstract this; others pass it to the player. Know the chain before playing.

The regulatory angle

Onchain games trigger the same MiCA obligations as other Web3 games when they involve custodial wallets, NFT marketplaces, or token transfers for EU players. The fact that the game logic is onchain rather than server-side does not change the regulatory classification of the wallet and marketplace functions.

Developers building onchain games for EU players need the same compliance infrastructure as developers building standard Web3 games.

Common questions about onchain games

Are onchain games fully decentralised? Most are partially decentralised. The game logic may be onchain, but the frontend, asset metadata, and some services often still run on traditional infrastructure. “Fully onchain” means the game could theoretically run without any single party’s servers.

What is Dark Forest? Dark Forest is an onchain strategy game built on Ethereum where players explore a hidden universe. It was one of the first widely-played onchain games and demonstrated that complex game mechanics could run in smart contracts.

Are onchain games more secure? In some ways — the rules are transparent and immutable. In others, less — public code is public to attackers too. Security audits are essential.

Can onchain games be upgraded? Smart contracts can include upgrade mechanisms, but these are complex and introduce risk. Many onchain games treat immutability as a feature — the rules never change.

Do onchain games work on mobile? Yes, via browser or app with a wallet integration. The gas cost model can be more of an issue on mobile, where players expect seamless free interactions.

Genesis Engine supports Web3 game developers building onchain and hybrid games for EU players. See how the compliance and payment rails work.