WebRTC Multiplayer is the practice of using WebRTC peer-to-peer connections to enable real-time multiplayer games and collaborative applications. Unlike client-server architectures where a central server handles all logic, WebRTC multiplayer uses peer connections for direct communication between players, reducing latency. Challenges include network topology design, handling latency and packet loss, cheating prevention, and managing player join/leave events. Core components: signaling server (coordinates connection establishment), STUN/TURN servers (NAT traversal), game loop with network synchronization, latency compensation, and connection management.