Distributed systems that must keep working even when some participants lie, crash, or send contradictory messages rely on Byzantine fault tolerant consensus. This 2D simulator renders a ring of replica nodes running the classic PBFT three-phase protocol — pre-prepare, prepare, commit — with animated message arrows travelling node to node. A configurable subset of nodes is marked Byzantine and, when equivocation is enabled, genuinely sends one value to one half of the ring and a different, fabricated value to the other half rather than a single consistent message — exactly the attack the protocol's 2f+1-out-of-N≥3f+1 quorum rule is designed to survive. Every honest node's vote count is computed from the actual messages it received each round. Push the faulty count past the safety bound and watch honest replicas on the minority side genuinely fail to reach a matching quorum and stall, in real time.