Hard Fork
Consensus● Common
A backwards-incompatible consensus rule change where new rules are looser than old rules. Old nodes reject blocks from new nodes. Creates a permanent chain split unless all nodes upgrade. Bitcoin has avoided hard forks; BCH, BSV were contentious hard forks.
Technical Notes
Examples: block size increase, new opcodes. Nodes must upgrade or follow old chain. Creates two competing chains with shared history. Replay protection needed to prevent transactions valid on both. Bitcoin's conservative culture strongly prefers soft forks.
Metadata
Visibility: Public
Created:1/3/2026by System