mazerunner-v0/environment.md

Game Design Document: “Crystal Grid”

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1. Concept Paragraph

“Crystal Grid” is a deterministic, turn-based strategy duel in which two mystic architects compete to align charged crystals on a sacred 3×3 energy grid. Each player channels a unique elemental charge—Solar (Player 1) or Lunar (Player 2)—and infuses crystals into empty nodes. The goal is to align three of one’s crystals horizontally, vertically, or diagonally to create a stable energy conduit. The available actions consist solely of placing a crystal at a chosen grid coordinate. This design is entirely unrelated to any negotiation or trading game; it’s a pure positional alignment challenge grounded in an original magical circuit theme.

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2. Roles and Win Condition

• Players:

  • Player 1: Solar Architect (mark → S)
  • Player 2: Lunar Architect (mark → L)

• Objective: Align three of one’s crystals (S or L) in a row, column, or diagonal.

• Win Condition:

  • A player wins if after their turn, three of their marks form an unbroken line.
  • The opposing player loses immediately.
  • If all nine nodes are filled and no line is formed, the outcome is a draw.

Decision rules:

1. Check alignment after every placement.
2. If both align simultaneously (impossible under alternation), the current mover’s alignment takes precedence.
3. Draw declared if maximum turns (9) are reached without a win.

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3. Turn Structure and Determinism

• Players alternate strictly (Solar → Lunar → Solar → ...).
• The first mover (Solar) always begins.
• The environment is fully deterministic.
• Random seeding affects only which player may go first if configured optionally; otherwise fixed for reproducibility via explicit seed.
• Turn limit: 9 turns maximum.
• All outcomes reproducible with identical initial seed and move sequence.

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4. Action Grammar (Machine-Parseable)

Allowed Action Tokens:
Each player may perform:

[Place: <row>,<col>]

where:

• <row> and <col> ∈ {1,2,3}
• Positions are 1-indexed (top-left is 1,1; bottom-right is 3,3)
• No repetition; cannot place where a crystal already exists.

Formal Pattern (regex):

^\[Place:\s*([1-3]),\s*([1-3])\]$

Example valid action:

[Place: 2,3]

Reason valid: Correct token keyword, valid 1–3 coordinates, comma-separated.

Example invalid action #1:

[Place: 0,3]

Reason invalid: Row out of allowed range (must be 1–3).

Example invalid action #2:

[Play: 2,3]

Reason invalid: Token keyword incorrect (‘Play’ not recognized).

In actual play, players will respond with \boxed{{[Place: 2,3]}} formatting, but the validation operates on the unboxed content.

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5. Game State Schema

Example runtime structure:

{
  "turn_count": 4,
  "current_player": "Solar",
  "grid": [
    ["S", "L", null],
    [null, "S", null],
    [null, null, "L"]
  ],
  "available_cells": [[1,3],[2,1],[2,3],[3,1],[3,2]],
  "winner": null,
  "is_terminal": false,
  "observations": {
    "Solar": "Previous move: [Place: 1,2] by Lunar.",
    "Lunar": "Your opponent placed [Place: 1,2]."
  },
  "history": [
    "Solar → [Place: 1,1]",
    "Lunar → [Place: 1,2]",
    "Solar → [Place: 2,2]",
    "Lunar → [Place: 3,3]"
  ],
  "seed": 42,
  "score": {
    "Solar": 0,
    "Lunar": 0
  }
}

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6. Initialization Rules

• The grid initializes to all null (empty).

• current_player set to "Solar" unless overridden by seed-based first mover rule.

• winner set to null, turn_count = 0.

• The seed controls any shuffle variation for first turn but not the grid generation.

• Initial observations describe the empty grid and player symbols:

  The Crystal Grid is empty. You are Solar Architect (symbol ‘S’). 
  Your charge begins first.
  

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7. Validation and Error Handling

Invalid move triggers:

1. Pattern mismatch — doesn’t match regex → “Action format not recognized.”
2. Cell out of range — row/col outside 1–3 → “Coordinates must be between 1 and 3.”
3. Cell occupied — attempted placement on non-null grid cell → “That node already holds a crystal.”
4. Not your turn — action attempted by the wrong player → “It is not your turn.”

When detected, environment returns set_invalid_move(player_id, reason).

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8. Terminal Conditions and Scoring

Check each turn:

1. After placement, verify if that player occupies any of the 8 winning lines:
   • Rows: (1,2,3)*(each same row)
   • Columns: (1,2,3)*(each same column)
   • Diagonals: (1,1)-(2,2)-(3,3) and (1,3)-(2,2)-(3,1)
2. If true → is_terminal = True, winner = current_player.
3. If turn_count == 9 and no winner → is_terminal = True, winner = "draw".

Scoring convention:

• Win → +1 score for winner, 0 for loser.
• Draw → 0.5 each.

Tie-break:

• None required beyond draw detection.

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9. Player Prompt Specification

When _generate_player_prompt runs, it assembles a structured text like below:

Prompt Outline:

• Identity blurb: “You are a mystic architect competing on the Crystal Grid. Align three of your charged crystals before your opponent does.”
• Display current board in a human-readable format with coordinates.
• List allowed actions summary:

  Allowed Action: [Place: row,col]
  where row and col are integers in {1,2,3}.
  

• Explain win conditions and turn rules.
• Example response instructions, including final boxed action.

Example snippets shown in prompt:

Example valid response:
I will charge the central node for structural balance.
\boxed{{[Place: 2,2]}}

If an invalid attempt occurs:

Invalid example (do not use):
\boxed{{[Play: 2,2]}}  <-- token must be [Place: ...]

Response format reminder: “At the end of your message, put your final answer within \boxed{{}} using one allowed action.”

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10. API Mapping Plan

reset()

• Clears grid and logs, initializes player identifiers and seed.
• Returns initial game_state, first observations, and references to legal actions.
• No winner or score yet.

step(player_action)

• Extracts action via _extract_answer_content().
• Validates syntax and legality.
• If valid: updates grid, increments turn count, checks for winner/draw.
• Updates observations to include transcript of both players’ actions.
• Returns updated game_state, new observation for next player, and completion flag.

_generate_player_prompt(player_id)

• Constructs full textual prompt described above with player perspective.
• Reads game_state: grid, turn count, player symbols, etc.
• Inserts few-shot examples of valid/invalid moves.
• Ends with explicit directive to produce \boxed{{[Place: <row>,<col>]}}.

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11. Copy-Check Against the Example

All entities, vocabulary, and schema in “Crystal Grid” are fully original:

• Theme: mystical crystal alignment, not trading, negotiation, or pricing.
• Roles: Solar and Lunar Architects, not merchants or diplomats.
• Objective: spatial pattern alignment, not bargaining success.
• Keys (grid, available_cells, seed, history, etc.) are unique to this design.
• Actions: [Place: row,col] tokens, entirely distinct from any negotiation-style [Offer] or [Accept].

This confirms full conceptual independence from the previous example while preserving structure needed for deterministic, turn-based API implementation.