ERAM Tiles rules

The goal is to complete the level's board by matching all of its tiles without losing. Each board completed for the first time unlocks the next level.

The core game is single-player and works offline: progress is saved locally after every accepted move and resumes after a sudden close. When online, the completion is sent to the server, which verifies it (it regenerates the board and replays your move log).

Additional modes exist in the code but are not open to the public yet:

• Race: a search for an opponent of up to 30 seconds, then one board for both with an equal tool pack; the first valid completion to reach the server wins. If one side withdraws, the other is not stopped.
• Private rooms: a 6-character code for the host, and an optional timer.
• Top 20: a ranking by the level confirmed by the server, respecting privacy and blocking.

Details of these modes (such as the race tool pack and the result when the timer ends) are still open decisions, so we do not describe them any further.

The game is played with picture-faced tiles, not playing cards. The level generator uses a set of faces identified by names such as AR1_001; one wide face (AR1_045) is currently excluded from the generator. All current face, template and background artwork is provisional until final artwork is approved.

• Level 1 is the reference board: 16 tiles, 3 of them face down.
• Every level is a deterministically generated board (the same level always gives the same board) built from several geometric templates, and each board carries a solution certificate guaranteeing it can be completed.
• The unit of progress is one level: completing a new board for the first time moves you up one level, and replaying an already-completed board does not repeat the rewards.

• Blocking: tiles overlap. A tile blocked by another (horizontally, vertically or by covering) cannot be picked. Unavailable tiles appear dimmed, and if you tap a blocked tile it shakes and the tap is refused.
• Selecting and matching: tap an available tile to select it, then tap another tile to match it; you can change your selection by tapping another available tile. Face-down tiles are revealed through interaction.
• The tray: a matched pair is lifted into two real tray slots, and the two tiles shatter inside it. The tray holds four slots.
• Refusal: if the tray cannot take the pair (three slots occupied), the entry is refused and the first tile stays selected.
• Last-slot warning: the game shows a hint when you are approaching the last tray slot.

Every accepted move is saved immediately. The engine does not wait for animations to finish before accepting your next move.

• Undo, Hint and Shuffle work only before a loss.
• Shuffle is random but guarantees the board remains solvable afterward.
• One extra tool of each kind (+1/+1/+1) is granted every 5 levels, only once per level.
• The number of tools in rooms and races is set by configuration (the current recommendation is 2 Undo, 0 Hint, 0 Shuffle) and remains an open decision.

The game has no per-level points table. Progress is the level number:

XP is currently stored only as a local "intent" and is not yet connected to the general rewards system; the XP curve after level 5 is an open decision. Rewards do not repeat when you replay an already-completed board.

• Win: completing the board. The result window then appears and the next board unlocks.
• Loss: happens immediately when play can no longer continue under the tray rules. After it, Undo, Hint and Shuffle no longer work.
• Retry: retrying is free and does not refill the tool balance.
• In a race: the first valid completion to reach the server wins; ties in arrival are settled by a row lock on the server with no tie window. When a room timer ends there is no winner and no progression reward (a provisional decision).

The sources do not spell out the exact condition at which a loss is declared beyond it being immediate and the tray having four slots, so we state only the above.

• Watch the tray: it holds only four slots, and a pair needs two.
• Heed the last-slot warning before you tap.
• Dimmed tiles are blocked; free them first by clearing what covers them.
• Use Undo, Hint and Shuffle before a loss; they do not work after it.
• The board has a guaranteed solution, so if you get stuck, try the free retry.

• Tile — a picture-faced piece on the board.
• Blocked — a tile covered or blocked by another and therefore not pickable.
• Tray — a strip of four slots that matched tiles move into.
• Match — choosing two available tiles to form a pair that goes to the tray.
• Undo / Hint / Shuffle — the three helper tools.
• Race — a competitive mode on the same board (not open to the public yet).
• Provisional — artwork not yet finally approved.