Shared hosting has one rule that quietly kills most multiplayer designs: you cannot run a persistent process. No WebSocket server, no daemon, no long-lived worker. Your PHP is born when a request arrives and dies when the response is sent.
I ran into this building a head-to-head word game — two players racing to guess the same five-letter word. The multiplayer part was fine. The problem was what happens when nobody else is online.
An empty matchmaking queue is the fastest way to kill a new game. So I needed a bot. And a bot, conventionally, is a process: something that wakes up every few seconds, decides on a move, and writes it somewhere. That is exactly the thing I could not have.
Here is what I did instead.
The constraint reframed
