Consensus protocol
Plain definition. A consensus protocol is the set of rules every participant in a decentralized system follows so they all agree on the same series of events and outcomes, with no administrator.
Technical definition. In the XRP Ledger, the consensus protocol’s main goal is to agree on a set of transactions for the next ledger version, apply them in a well-defined order, and confirm everyone got the same results, after which that ledger version is considered validated and final. According to the XRP Ledger documentation, each participant in the network chooses a set of validators, and this list is called a Unique Node List (UNL). As the network progresses, each server listens to its trusted validators, and once a large enough percentage of them agree on a set of transactions and the resulting ledger, the server declares a consensus. Consensus continues unimpeded as long as fewer than 20% of trusted validators are faulty, while confirming an invalid transaction would require over 80% of them to collude.
On this site
On this site, Consensus protocol comes up in How is XRP kept secure if it isn’t mined?, Does the default validator list make the XRP Ledger centralized?, Has the XRP Ledger ever halted, forked or lost funds since 2012, and what happened? and How does XRP compare with Bitcoin and other major coins?.
Source
Consensus Protocol (xrpl.org), read October 1, 2026.