Make a multiplayer game

From nothing to two tabs on one course, with the race kit: a multiplayer game that already works, for you to change.

1. Pick a kit

npm create gameable -- --list

prints every template, one line each, with race marked as multiplayer:

Kit	Players	What it is
`race`	1-12	obstacle race with jumps, sweepers, checkpoints and places

Race is also hosted on the Play page. Play together opens a room on the hosted room server; copy the link the corner shows into a second tab and you are two players, with nothing installed.

2. Scaffold

npm create gameable my-race -- --template race
cd my-race
npm install
npm run build:guest   # Play Solo's authority runs the wasm guest
npm run dev           # http://localhost:5199

The page plays solo: a room of one, the authority in the page. WASD walks, Space jumps and the mouse orbits. Solo starts after a three-second wait and a three-second countdown. Falling returns you to your last checkpoint. Paste a published link in Your character or use ?look= to choose your look.

3. Start a room server

In a second terminal, in the same directory:

npx gameable serve --direct   # the room server, ws://localhost:8790

--direct runs src/game.ts as it is, with no build. It reads the file once, so restart it after an edit. It takes pages from http://localhost:* and http://127.0.0.1:*.

4. Two tabs

Open http://localhost:5199/?room=new&rooms=http://localhost:8790. Once it joins, the corner shows a four-letter code and Copy link. Open the link in a second tab: two racers on one course, each moving in their own tab and seen in the other. The second player starts a five-second wait, followed by a three-second countdown. Race to the finish line to see your places.

The address picks the room: ?room=new makes one, ?room=CODE joins it, ?room=quick joins any open one, and no ?room= plays solo. ?rooms= works only on a local page; a deployed game talks to its own site's room server.

5. Change something

The layout and tuning are in src/course.ts. Change walkSpeed and runSpeed in RULES from 4 to 5, restart serve --direct, and reload both tabs. Both racers now move faster; prediction uses the same movement system on the page and the authority. Rebuild the guest before trying Play Solo after an edit.

Run the kit's tests, which drive the authority headlessly without a browser:

npm test

Make a multiplayer game ​

1. Pick a kit ​

2. Scaffold ​

3. Start a room server ​

4. Two tabs ​

5. Change something ​