Build your own Chess.

# Build an original game inspired by Chess

You are an experienced game designer and gameplay engineer. Build a working, polished MVP from the brief below. Implement the core journeys end to end; a static mockup is not sufficient. Inspect the current environment, make sensible implementation decisions, and get started. Ask a question only if a missing answer genuinely blocks implementation.

Starting platform: Web. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original local two-player browser chess app called Boardroom. The main journey is starting a game, playing legal moves on one device, reviewing the move history, and saving or exporting it. Use standard chess rules through a tested rules library and original board/piece assets. The MVP does not require an AI opponent or online matchmaking.

## Design
Use an original high-contrast board with coordinate labels, a clear side-to-move indicator, move list, captured-piece information, and promotion picker. Support click/tap selection and keyboard square navigation in addition to dragging. Show legal destinations and check status accessibly, with board flip and reduced-motion settings.

## Features
1. Rules: delegate legal move generation and validation to a tested chess library such as chess.js. Cover check restrictions, castling rights, en passant, and all promotion choices; never infer legality from piece animation.

2. Game outcomes: distinguish checkmate, stalemate, resignation, draw agreement, and supported repetition/move-count/insufficient-material conditions. Document whether a draw is automatic or claimable in this casual local edition.

3. Play controls: start a new standard game, flip the board, pause/resume interaction, and offer a confirmed restart. Provide analysis-style undo only when explicitly enabled and visibly mark the game as casual.

4. History: maintain algebraic move notation, step through completed-game positions without mutating the live game, and export PGN. Import a bounded valid PGN through the rules library with clear errors.

5. Persistence: save initial position, move sequence, outcome, and settings after every move. Reconstruct the engine by replaying validated moves on reload; preserve history-dependent repetition and castling state.

## Tech stack
Use TypeScript with a browser board component and a maintained tested chess rules library, preserving its license notices. Wrap library state in a small application engine independent of rendering. Persist the starting position and full move sequence, not just the final FEN, because history affects draws. Keep imports bounded and provide a local-save fallback. Omit clocks initially to avoid pretending pause is compatible with competitive timing.

## Data & behavior
Game {id, initialFen, moves, result, resultReason, casualUndoEnabled, paused}; Move {from, to, promotion, san}; ReviewState {ply}; Settings; ExportMetadata. Validate every imported move and only publish a successful reconstructed session after complete validation.

Acceptance checks and scope:
Test castling through attacked squares and after rook movement, en passant expiry, underpromotion, a pinned-piece move, checkmate versus stalemate, repetition after reload, and malformed PGN. Confirm board review cannot alter active play. Exclude copied piece sets, AI strength claims, tournament-clock rules, online ratings, and matchmaking.

## Originality and assets
The named product is a reference for general workflows only. Use an original product name, visual identity, wording, layout, and assets. Do not copy proprietary code, branded logos, distinctive screens, private APIs, paid templates, or protected media. Use original or appropriately licensed sample data and assets. Build from this brief rather than scraping the reference service. Do not imply affiliation with the referenced company.

## Implementation quality
- Make every visible control work, with clear loading, success, empty, validation, and failure states. Remove controls for unimplemented features.
- Support the target platform and responsive or resizable layouts where appropriate. Use platform-appropriate accessibility semantics, labels, keyboard operation, visible focus, sufficient contrast, and reduced-motion preferences. Provide alternatives for drag-only interactions.
- Validate inputs at the relevant boundary. Treat imported or user-generated content as untrusted; render it safely. Confirm destructive actions or offer undo.
- Keep state changes reliable across navigation and reloads. Never silently lose edits. Handle persistence and network errors with an actionable message.
- Keep the scope realistic. Prioritize the complete primary journey. If a custom Features section differs from the baseline, update the data model, design, and acceptance checks to match it; explicit custom requirements take precedence over baseline assumptions.
- Provide realistic original sample content and a useful empty state. Keep sample data clearly separate from user-created data.

## Delivery and verification
1. Inspect the repository and outline the implementation in a few sentences.
2. Implement the app and connect its actual data flow. Continue until the primary journey works.
3. Run appropriate checks and test the acceptance cases above on the target platform. Verify responsive layouts and keyboard navigation when browser tools are available. For native projects, build with the available SDK and test an emulator or device when possible; report any missing native verification honestly. For games, verify the rules and gameplay loop, not only the menus.
4. Fix observed failures, then provide the runnable result, setup/run instructions, a brief explanation of what is implemented, and any specific configuration or verification limits.

This is a focused MVP. Do not add billing, AI services, or unrelated features unless explicitly requested in the brief. Start building now.