Real Time Multiplayer in HTML5 - Build New Games

The article explains why HTTP is enough for turn-based or asynchronous browser games but too slow for real-time play, then shows a browser stack built with socket.io, Node.js, Express, and HTML5 canvas. It also frames the demo around a simple two-player lobby and a shared game world that runs on both server and client.

Reading notes

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• HTTP POST and GET work for semi real-time and asynchronous games, but real-time games need messages sent and received many times per second.
• socket.io is presented as the main networking layer because it supports web sockets and falls back to other transports when needed.
• Node.js and Express are used together to serve files, route requests, and host the socket.io server cleanly.
• The client side connects with a small HTML file, loads the socket.io script, and listens for the connection event.
• The demo focuses on two blocks moving in the same space so the multiplayer logic stays visible.
• Frame-rate independence is handled with delta time so movement stays consistent across devices and browsers.
• The article recommends exposing tweakable values, and the demo uses Dat.GUI for live changes.
• The networking model uses a simple lobby where a client joins an existing game or creates a new one.
• The server keeps authority over game state, while the client also runs local logic to stay responsive.
• The server uses a fast physics loop and a slower state-update loop to process input and broadcast state.
• The client uses prediction so local input changes position immediately instead of waiting for the server reply.
• Other players are smoothed with interpolation by storing server messages and drawing positions slightly behind server time.
• The shared game code lives in game.core.js so the same functions and data structures can run on both server and client.
• The demo also stores input sequences so the client can drop acknowledged inputs and reapply the remaining ones.
• The article ends by pointing to the demo, the source code, and further reading on multiplayer networking and real-time game programming.