Smart contracts that assumed block.timestamp is strictly monotonic and low-jitter may break. The new consensus uses a , smoothing out malicious timestamp manipulation but breaking naive TWAP oracles.
Several opcodes are changing behavior. Smart contracts relying on old gas schedules or specific block timestamps may behave unexpectedly. The upcoming HardX updated testnet has been running since August 2025, and early reports show a 12% reduction in average gas costs.
