The game and the family — the feedback function.

The play is a code space: six positions, each holding one code from the game’s keyboard. The secret and every guess live in that space, so one validation and one comparison cover the whole family.

Every game snapshots a keyboard when its first player joins: the room’s emoji set — the full keyboard, or a fresh random subset when the room sets cell_count — becomes the game’s cell_codes. A code is XXYY — column then row, two digits each — addressing one cell of the sprite sheet (Codemojex.EmojiSet). The code space of the play is those codes over six positions.

The secret is drawn from the same snapshot: EmojiSet.secret_from(cell_codes) takes six distinct codes from the game’s keyboard (@code_length 6), and Codemojex.Rooms mints the game as a branded GAM around it. The keyboard the player taps and the secret the player chases index the same cells — no guess can name a symbol the secret could not contain.

A guess is exactly six codes, enforced at the function head — Codemojex.Guesses.submit(game, player, emojis) when length(emojis) == 6 — and every code must be one of the game’s cell_codes. Anything that is not a valid six-element guess falls to the catch-all submit/3 clause and answers {:error, :bad_guess}. The acceptance catalog pins the accepted path: a guess submitted on the lane is scored and reaches the leaderboard (rooms-and-games.stories.md).

Grounding — lib/codemojex/game.ex (Codemojex.Guesses.submit/3: the when length(emojis) == 6 guard, the {:error, :bad_guess} fall-through) · lib/codemojex/emoji_set.ex (secret_from/1, @code_length 6, the XXYY code shape) · stories/rooms-and-games.stories.md.

What a guess reveals about the secret is the defining element of the family — fix the code space and the feedback function, and the game is fixed.

The Mastermind board game set the loop in the early 1970s: a codemaker hides a code, a codebreaker probes it, and every guess is answered by a report. The family that grew around it varies the number of positions, the symbol alphabet, and — the defining element — the feedback function: what a guess reveals. The board game’s pegs are one choice of feedback; a numeric score is another; silence until the end is a third.

In Codemojex, one authority computes the report. Codemojex.ScoreWorker — “the scoring consumer — the authority” — drains the guess queue and scores every guess with Scoring.score(secret, emojis), writing the guess as a branded GES with its points, keyed to the PLR whose lane carried it. The host that accepted the guess never scores; the consumer does.

The six position comparisons fold into one report per guess. For a classic game the worker publishes it as a scored event, and the report is thin — a name and a percentage, not the positions that matched nor the codes that slipped. The distance-to-points law behind the number (100 − 20·d per position, summing to 600) is C4’s ground; this dive stays with what a guess reveals, and to whom.

The report is also stable. The same secret and guess always score identically — a re-delivered guess is safe (scoring.stories.md) — so the feedback function is a pure function of the pair, which is what lets a queue-fed consumer be the single authority over it.

Grounding — Codemojex.ScoreWorker in lib/codemojex/game.ex (the authority; Scoring.score(secret, emojis); the classic scored publish) · stories/scoring.stories.md (six scenarios; the purity law).

The three modes are one engine under three policy sets, and the feedback policy is where the family forks.

The fork is a pure lookup: Codemojex.Rooms.policies_for/2 maps the game’s type — plus the tournament marker — to its four policies, snapshotted onto the GAM at start. The feedback values state the family membership in one word each: feedback: "score" for type:"classic", ordinary room and Golden-Room tournament alike; feedback: "none" for the blind type:"golden".

The blind contract is exact. A golden game “stores the guess but emits NO per-guess feedback (the blind contract): the score is sealed until reveal” (Codemojex.ScoreWorker). The score exists server-side from the moment the worker runs; no scored push fires in-flight, and the player’s own history withholds points (golden-blind.stories.md). At close the sealed pass emits one revealed event — the now-exposed secret, the final board, the payouts — “the first and only results a blind client receives”.

A Golden Room is deliberately not a fourth feedback shape. It is a live tournament on the classic base — type:"classic" with golden:true — so its feedback stays "score" and the contest plays in the open; what forks there is settlement and economy, C4’s and C5’s ground. Feedback is policy, not code: a new mode is a new row of values over the same six-position play.

Grounding — lib/codemojex/rooms.ex (policies_for/2; the one revealed event at the sealed close) · stories/golden-blind.stories.md.