sometimesyour first change
this tutorial changes the counter to add two on each click and verifies that both players receive the updated value.
1. open the project
finish the quickstart, then open the my-game folder in your editor. client.ts creates the screen; server.ts owns the shared count. game.json describes the game. package.json lists dependencies and commands. you do not need to edit node_modules or output.
2. change the rule
replace server.ts with this code. init creates a new match at zero. action accepts only the increment command and adds two. view returns the count to each player. only the server changes the shared score, so editing a label cannot change the rules.
import { defineGame, GameError } from "@sometimes/games/server";
export default defineGame({
init: () => ({ count: 0 }),
action(state, name) {
if (name !== "increment") {
throw new GameError("invalid", "unknown action.");
}
state.count += 2;
},
view: state => ({ count: state.count }),
});3. change the button
in client.ts, find the line below and change add one to add two. keep the existing click handler: it sends the increment action, handles errors and renders the server's response. the subscription updates the other player's screen.
button.textContent = "add two";4. check the result
save both files. stop the simulator with Ctrl+C, run npm run dev again, and reload its printed URL. both counters start at 0. click add two in the first screen: both should show 2. click it in the second: both should show 4. try mobile view and disconnect/reconnect. restarting this local simulator starts a fresh match; production rooms persist their state.
npm run dev5. package the game
run npm run build to create output/game.sometimes.json, which you can upload in the developer dashboard. further changes follow the same process: add state fields and validated actions on the server, return permitted fields in view, and render the result in the client. the Wordle example demonstrates this structure in a complete game.