Hard Fork
A permanent rule change to a blockchain that splits it into two chains — incompatible with the old software.
A hard fork changes a blockchain’s rules in a way that old software rejects. Everyone must upgrade, and if part of the network keeps running the old rules, two separate networks emerge with shared history — which is how communities sometimes split, Bitcoin Cash and Ethereum Classic origins, for example.
Why forks are decentralization in action
Any participant can fork a public chain — that’s a feature of open source. The market then decides which fork holds value. Forks also expose political rifts: who controls updates, nodes, and the “official” brand all become visible when a chain splits.
What analysts watch
Whether a fork is forced (minority rejects a majority change) or voluntary (driven purely by user choice) tells you about governance health. W3D’s governance pillar examines how transparently consensus changes actually are.
Related terms
Consensus Mechanism, Governance, Node, Soft Fork, Blockchain