Games

Four ways, and every one of them ends at a session id. A room code — short, shareable, short-lived — for the person sitting next to you. A direct invite by email or screen name, pending until it is accepted. A friend graph formed by mutual accept. And an open queue: one Durable Object per game pairs waiting players, bucketed by Cloudflare's own edge geolocation and by skill, widening each player's band the longer they wait until someone qualifies.

A second Durable Object holds every online player's socket and pushes match-found, invite-received and friend-request in real time, over the Hibernation API — so a connection waiting on nothing bills no duration.

The session is the same for every game: membership bound to a signed-in user, a lifecycle, hidden per-player state, an alarm-driven deadline, a durable result in your D1. What a game is plugs in behind that, and three patterns cover most of them.

Simultaneous — everyone submits a hidden choice and the server resolves them together; battle ships on it, a duel or an N-player free-for-all of secret attacks and blocks. Turn-based — the helper owns turn order; connect-n ships on it, which is tic-tac-toe at 3×3, Connect Four at 7×6 and gomoku at 15×15 from the same model. Wagering table — a persistent table with a bet book and settlement; craps ships on it.

Those three are examples, not the menu. Write your own game against the pattern that fits and register it; only the rules are yours.

The server holds what no client may: the hidden hand, the shuffle, the roll. A game model's logic is pure and cannot touch a database, so a move is validated and resolved in one authoritative place.

For anything with stakes, every session mints a random seed at creation and publishes its SHA-256 hash up front, then reveals the seed when the session ends — so a player can replay the seed afterwards and verify every roll the table made.

Two numbers per player, per pool: a skill rating that moves both ways with every result, and an experience total that only ever rises. They are separate deliberately — one number cannot both rank a player fairly and reward them for turning up.

The algorithm is a choice, not a hardcode. Elo for transparent 1v1, Glicko-2 when a returning player should not be rated on stale form, TrueSkill when you need to rate teams. Register your own if none of them fit. Wiring a 1v1-only algorithm to a four-player game fails on deploy rather than on the first result.

Pools are named, so several games can share a ladder or each can keep its own — and a pool is exactly what the open queue buckets on.

Submit a score, read the standings — daily, weekly and all-time from the same submission. A rating estimates what will happen; a leaderboard records what did, and they are different products for a reason.

A finished session publishes to it one way, so the board cannot disagree with the result that produced it.

A per-user balance in your own D1 — chips, gold, gems, credits, whatever you call it. What makes it a ledger rather than a column is that a stake can be held before a game and settled after: a hold a player cannot cover rejects the action, and a deterministic model that replays re-emits the same effect and pays exactly once.

Buying the currency is the payments capability, and a product's catalog entry can grant into the ledger directly — so a purchase on any of five rails tops up the same balance.

Before an Android build reaches production, a new personal developer account owes Google a closed test: twelve testers, opted in, for fourteen continuous days. Lose one on day nine and the clock effectively restarts, and no screen in the Play console tells you where you stand.

That is the capability nobody puts on a comparison table, and it is the one that decides your launch date.