Vitalik Buterin wants to replace the Casper FFG system with a new one called Minimmit to improve how

Vitalik Proposes Replacing Casper FFG with 'Minimmit'—Faster Finality, Lower Fault Tolerance

Vitalik Buterin is floating a big idea for Ethereum's consensus layer. In a post on X, he proposed swapping out Casper FFG—the current finality gadget—for something new called Minimmit. The goal? Streamline how the chain reaches finality, even if it means accepting a bit more risk.

Here's the technical trade-off. Casper FFG takes two rounds: validators sign once to "attest," then again to "finalize." Minimmit cuts that down to one round. Faster, simpler. But there's a catch: the fault tolerance drops from 33% to about 17%. So if more than 17% of validators go rogue, things could get messy.

But Vitalik argues it's still the right move. Why? Because in many attack or bug scenarios, Minimmit makes it more likely the network ends up with multiple competing chains—a "fork" situation—rather than finalizing a bad block. And forks? The community can coordinate to fix those. Finalized bad blocks? Much harder to undo.

His take: it's safer to have no finality for a bit than to have the wrong finality. On balance, Minimmit might be the better bet.