The Hidden Complexity of Two-Player Browser Games — A Practical Guide to Keyboard Input

I run 2playerfun.com , a site dedicated entirely to two-player browser games where both players share one keyboard. It's a niche that turned out to have more technical depth than I expected. When I started, I assumed local multiplayer was the easy case. No netcode. No latency. No matchmaking. Just two players, one keyboard, browser-side state. What could go wrong? What could go wrong, it turns out, is that two people pressing keys on a single keyboard at the same time is a surprisingly hostile e