Game jams

A global leaderboard for your jam game, in the time it takes your coffee to brew. Free, no player accounts, works in web builds on itch.io — and the board keeps running long after the jam ends.

Why bother, mid-jam?

Because during the rating period, a leaderboard is a retention machine. Raters play a jam game once, rate it, move on — unless there's a score to beat. A visible global board turns "played it" into "played it four times trying to knock #1 off", and players who replay leave better ratings and comments. It's the cheapest engagement feature you can ship in a jam.

The parts that matter for jam conditions:

• Players need no account. Anonymous login is a persistent device ID — raters land on the board on their first run, zero sign-up friction. (Nobody creates an account to rate a jam game. They don't have to.)
• Web builds work. Board reads are CORS-simple, so an itch.io-embedded HTML5 export reads leaderboards with no proxy or server of yours. See Web export.
• It's free. No card, no tier to pick mid-jam. Register a game, get an API key, go.
• Daily and weekly boards are automatic. Every game gets all-time, weekly, and daily boards with automatic archiving — a "today's best" board resets itself while you sleep.

The 3-minute path, by engine

Godot 4 — the drop-in

Install the CheddaBoards addon from the Godot Asset Store (enable the plugin; the autoload registers itself), then:

func _ready():
    CheddaBoards.set_api_key("cb_my-jam-game_xxxxxxxxx")
    CheddaBoards.set_game_id("my-jam-game")
    CheddaBoards.leaderboard_loaded.connect(_on_leaderboard)
    await CheddaBoards.wait_until_ready()
    CheddaBoards.login_anonymous()   # nameless — the server names new players (Player_1248) until they pick one

func _on_game_over(score: int, streak: int):
    CheddaBoards.submit_score(score, streak)

func show_leaderboard():
    CheddaBoards.get_leaderboard("score", 100)

func _on_leaderboard(entries: Array):
    for e in entries:
        print("#%d %s - %d" % [e.rank, e.nickname, e.score])

That's the whole integration. Full walkthrough: Godot quick start. Starting a game from nothing at hour zero? The template is a working project with menus, sign-in, and a leaderboard scene already wired — replace the example game with yours.

Unity — one file

Copy CheddaBoards.cs from the Unity SDK repo into your project — no packages, no scene setup:

var cb = CheddaBoards.Instance;
cb.SetApiKey("cb_my-jam-game_xxxxxxxxx");
cb.SetGameId("my-jam-game");
cb.OnLoginSuccess += (nick) => canSubmit = true;
cb.LoginAnonymous();                      // nameless — see the Godot note above

// at game over:
CheddaBoards.Instance.SubmitScore(score, streak);

Full walkthrough (and a complete demo game to crib from): Unity quick start.

Anything else — two HTTP calls

Bevy, Love2D, PICO-8 exports, hand-rolled JS — if it can POST JSON, it can have a leaderboard. Generate a persistent player ID client-side, then:

# submit a score
curl -X POST https://api.cheddaboards.com/scores \
  -H "X-API-Key: cb_my-jam-game_xxxxxxxxx" \
  -H "X-Game-ID: my-jam-game" \
  -H "Content-Type: application/json" \
  -d '{"playerId": "dev_1730000000_1a2b3c4d", "gameId": "my-jam-game", "score": 1500, "streak": 5}'

# read the board
curl "https://api.cheddaboards.com/leaderboard?sort=score&limit=10" \
  -H "X-API-Key: cb_my-jam-game_xxxxxxxxx" \
  -H "X-Game-ID: my-jam-game"

Generate playerId once per player (random, e.g. dev_<unixtime>_<random>), store it locally, reuse it — that's the whole identity model. Never hard-code one: every copy of your game would be the same player. Full surface: REST quick start.

Jam checklist

• [ ] Register the game before the jam starts — cheddaboards.com takes a minute, but it's a minute you won't want at hour 47. (It's infrastructure, not gameplay — the same as making your itch page ahead of time, and fine under standard jam rules. If your jam is unusually strict about pre-work, check its rules page.)
• [ ] Log in nameless (login_anonymous() with no argument) — players keep any name they set, and new players get a generated Player_1248-style name automatically
• [ ] Submit only after login completes (from game-over code, not before login_success / OnLoginSuccess)
• [ ] Web export: the file must be index.html, and test it served (python3 -m http.server), never from file://
• [ ] Turn debug_logging off before you build
• [ ] Put the leaderboard on the game-over screen, not behind a menu — raters should trip over it
• [ ] Show the current #1 score next to the player's on that screen ("Best: 48,200 — beat it?") — that line is the replay trigger

Jam-shaped details

Rate limits won't bite you. Submits are throttled at one per player per board every 2 seconds — a normal game-over loop never notices. If you're doing something weirder (per-kill submits, presence heartbeats — it's been done), targeted boards are throttled per board, so spreading writes is fine.

Rating-day traffic is nothing to plan for. A front-page itch spike needs nothing from you — no quotas to raise, no config to change, no bill at the end.

Anti-cheat is optional and probably worth skipping at first. Play sessions and time validation exist (Anti-cheat) and jam leaderboards do attract the occasional 999999999. For a 48-hour jam, ship without it and turn on score caps from the dashboard's Security tab if someone misbehaves — no code change needed for caps. Add play sessions if you keep the game alive after.

The board outlives the jam. Scores live on the Internet Computer — the leaderboard keeps working after the rating period, after the jam page goes quiet, for as long as you care. If the jam game becomes a real game, everything carries over: same API key, same board, same players.

Common jam-weekend issues

What you see	Fix
"Not authenticated" on submit	Submit ran before login finished — submit from your game-over code
Blank screen on itch.io	Export must be named index.html; test it served locally, not from file://
Empty leaderboard	Game ID doesn't match the dashboard
Score rejected	You enabled time validation but aren't starting play sessions — turn validation off, or start sessions
Player's name reverted	You're passing a name to login_anonymous() every launch — log in nameless

Full list: Errors.

See also: Godot quick start · Unity quick start · REST quick start · Web export · Timed leaderboards