XI Cup

XI Cup is a browser-based soccer fantasy draft game: build an all-time starting XI from limited player packs, optimize chemistry, and simulate cup runs — solo or 1v1 with friends.

This repo is a dependency-free MVP based on the product requirements doc.

Run

Open index.html in a browser.

No install step is required. The solo prototype stores state in browser localStorage.

Built in this MVP

• five-player draft stacks
• curated and random pack rolls
• viewed stack burn/discard logic
• two free rerolls and capped paid rerolls
• manager picks
• formation picks across the 12 PRD formations
• automatic best-slot player placement
• manual field-slot swaps
• position fit penalties
• club, nation, line, combo, manager, and experience rating breakdowns
• one local saved team slot
• AI bot teams generated through the same draft/rating rules
• solo match simulation using the PRD Elo-style win probability
• local leaderboard
• online architecture notes
• smaller 3D-style field layout
• friend 1v1 mode with invite links and best-of-5 series (PeerJS, honor-system)
• World Cup-style group stage plus knockout cup simulation
• larger player pool with more curated era/team packs
• rebalanced game ratings with a wider spread across tiers
• generated card-sheet art pipeline notes

Rating scale

Player data keeps a peakRating estimate for historical flavor, but gameplay uses a rebalanced rating:

• S: 88-100
• A: 76-88
• B: 62-78
• C: 48-64

This keeps true all-time signatures rare while making ordinary starters, role players, and lower-tier cards matter as draft tradeoffs.

Random mixed packs also use tier weighting, so S-tier cards are rare outside curated packs.

Important product decision

Solo play can stay client-side while the game rules are still changing. Online play should not trust client-side state. Draft RNG, paid rerolls, saved teams, match results, and leaderboard records need server authority before real competitive play.

See docs/online-architecture.md. See docs/card-art-pipeline.md for the recommended generated card-sheet workflow.

Good next engineering step

Split app.js into:

• data.js
• rules.js
• state.js
• ui.js

That keeps the current static game intact while making the rules reusable for a future API server.