What a verifiably random game proves, and what players still need to check

Guide | Documentation reviewed September 17, 2026.

A random-looking result and a verifiable result are different things. A VRF produces an output with a cryptographic proof tied to its input and public key, allowing a verifier to check the calculation rather than simply accept a server's claim.

On Arc, that distinction is relevant because the chain's PREVRANDAO value is always zero. A game cannot obtain unpredictable draws merely by reading that field.

D20DAO provides a concrete implementation to examine. Its public documentation describes replaying epoch evidence and the request's VRF proof, then checking how the resulting number maps to a die, selection or shuffle. Reading a displayed number is not the same as performing that verification, and replay still requires trustworthy chain context.

For a player, the next questions concern the game itself. Were the prize list and odds fixed before the draw? Can the result be ignored or rerolled? Does the contract actually pay the promised reward? Can an administrator change those rules?

A proof helps answer how a particular number was produced. It does not by itself guarantee payment, hide a player's cards, eliminate operator downtime or make every possible game rule fair. D20DAO's single-operator and upgrade-authority assumptions remain relevant even when an individual proof verifies.

Sources: Arc EVM differences, D20DAO verification guide, security model, Chainlink VRF security considerations.