Dojo and Starknet: Where 'Provable' Games Live and Die On-Chain

In most roguelikes, when your hero dies, the run is over. In Loot Survivor, when your hero dies, the death is recorded on a public blockchain for ever. That small, grim detail captures what a group of developers on Starknet has been building: games where every attack, every loot drop and every death is a transaction anyone can verify.

The toolkit behind many of them is Dojo, an open-source engine for fully on-chain games, and it's one of the most interesting corners of blockchain gaming that most players have never heard of.

First, what is Starknet?

Starknet is an Ethereum layer 2 network built by StarkWare, the same company whose rollup technology powered Immutable X. It uses zero-knowledge proofs (specifically STARKs) to bundle huge numbers of transactions, prove they were all computed correctly, and post that proof to Ethereum. Programs on Starknet are written in Cairo, a language designed to make that kind of proof efficient.

For games, this matters because proving computation is Starknet's whole specialty. The more of a game's logic you can run and prove, the more of the game can live on-chain.

What Dojo does

Dojo calls itself a provable game engine. In practice, it gives Cairo developers the building blocks they'd otherwise write from scratch:

• an entity-component-system structure, the same pattern many modern engines use, for organising game objects and logic;
• tools to index on-chain game state so a game client can display it quickly;
• local tools for testing a world before deploying it.

If that sounds similar to MUD on Ethereum, it is. Both frameworks come from the same movement of "fully on-chain games" and "autonomous worlds", where a game's rules live on a blockchain so anyone can read and extend them. (Our MUD explainer covers that side.)

The Loot connection

Dojo's community has deep roots in Loot, the 2021 project that gave away 8,000 text-only "bags" of fantasy items. (Read our Loot story.) Builders from the Loot and Realms community moved to Starknet and started making actual games:

• Loot Survivor, an arcade-style dungeon crawler where you pay an entry fee, send an adventurer into the dark and try to survive as long as possible. Beasts, gear and outcomes are determined on-chain, and death is permanent.
• Eternum, a strategy game set in the Realms world, with resources, armies and territory managed on-chain.

Other Starknet teams have built games such as Influence, a space strategy game set in an asteroid belt.

Logging in without the pain

On-chain games ask for a lot of transactions, which used to mean a lot of wallet pop-ups. Starknet accounts are smart accounts by design, so the ecosystem has leaned on session keys: you approve a game once, with limits, and it can act for you during play. Cartridge, a company closely tied to Dojo, built a gaming wallet called the Controller around that idea, using passkeys instead of seed phrases. (For the concept, see our account abstraction explainer.)

The trade-offs

Provable games have the same issues as every fully on-chain design. They can feel slower than normal games. Someone has to pay for transactions. Public state makes hidden information hard. And small audiences make it difficult for studios to sustain themselves.

Some of these games also involve paid entries and token prizes, which raises the same questions as any game with real-money stakes. Players should know exactly what they're paying, and why.

Why it matters

Dojo and Starknet are where the "games, not just items, on-chain" idea is being pushed hardest. Most projects are small and experimental, and their audiences are tiny next to mainstream games. But if you want to see what a blockchain does when it's the game engine rather than the gift shop, this is where to look.