LINK//9 — Grid Protocol

A free, source-available, non-commercial cyberpunk-themed card game for your browser. Hack your way across a 3×3 grid: place programs, link their arrows into chains, trigger combos and crash your rival's hit points before they crash yours.

https://pizzattack.github.io/Link9/

Play online or play locally. No install, no build step, no account, no ads. Works on desktop and phones.

Screenshots

Play

• Online: play from the github pages
• Locally: download the repository and open index.html in a recent browser (Chrome, Edge, Firefox, Safari).

How it plays

Each side has a 3×3 grid, a 25-program deck and a hand of 5. Every turn you place one program on an empty square.

• Links. Programs carry arrows on their sides and corners. Two neighbouring programs are linked when their arrows face each other. A group of linked programs is a chain.
• Symbols. Programs carry symbols: attack, shield, revive or neutral. When a chain holds 3 symbols or more, whatever their family, it triggers a combo. The most represented family decides the effect: attack hurts the rival, shield heals you, revive wakes your disabled programs. Neutral symbols only help reach 3.
• Abilities. Many programs also have an ability: on placement, at the start of your turn, on a combo, or when reactivated. Abilities rotate, lock, destroy, swap, discard, add links or symbols and more.
• Win by taking the rival's HP to 0 (you both start at 7, never above 10). Lose if your grid is full at the start of your turn.

The in-game Rules screen and the guided Tutorial cover everything in a few minutes.

Features

• 180 original programs in 4 rarities (common, uncommon, rare, ultra-rare), with 20 effect types and 162 illustrations.
• Random fight: a quick game against the AI with freshly drawn decks.
• Campaign:
  • build a 25-program deck from your collection;
  • win fights to choose 1 of 3 reward programs (the others become shards);
  • spend shards at the Merchant (random program, pick-1-of-5, shard exchange);
  • improve or scrap programs at the Workshop;
  • a tenacity reward softens defeats.
• Illustrated comic: 72 pages unlocked fragment by fragment as you win campaign fights.
• Deck editor with filters by rarity, symbols and links.
• Guided tutorial played on the real board.
• AI opponent that searches moves with a Monte-Carlo style evaluation, without ever seeing your hand.
• 7 languages: English, Français, Español, Italiano, Deutsch, 简体中文, 日本語.
• Sound: sound effects for every game event and two music playlists (ambient and battle), with volume sliders.
• Responsive: layouts for desktop, tablet and phone, with touch drag-and-drop.
• Installable and offline-ready (PWA): add it to your home screen and play without a connection once it has loaded. Progress is saved in your browser (localStorage). Nothing is sent anywhere.

Install it as an app (iPhone, Android, desktop)

• iPhone / iPad (Safari): open the game, tap Share → Add to Home Screen → Add. It then launches full screen with its own icon. Open it once online and play a few screens so that images and sounds are stored; after that it works offline.
• Android (Chrome): menu ⋮ → Install app (or Add to Home screen).
• Desktop (Chrome / Edge): click the install icon in the address bar.

Notes: iOS keeps stored data for a limited time if the app is not used for several weeks, and clears it if you clear Safari's website data. Saves live in the browser's storage, so back up anything precious. After an update, close and reopen the app once to get the new version.

• tools/make-screenshots.mjs takes the game screenshots (English, desktop + phone) and builds the GitHub social preview and the itch.io cover/banner in one command (see below).
• Scene mode: index.html?scene=<home|combat|combat-low|campaign|merchant|workshop|deck|reward|rules|tutorial|comic>&lang=<en|fr|…> shows a reproducible demo state (fixed random seed, no save read or written, sound off). It is what make-screenshots.mjs photographs.
• tools/make-icons.py regenerates the favicon, the Apple touch icon and the PWA icons from ui/skin/logo-round.png (pip install pillow, then python3 tools/make-icons.py from the repository root).

About this project

LINK//9 is a personal, non-commercial fan project. I love the gameplay of Card City Nights (grid placement, linked arrows, chain combos) but not its art style and lore, and I wanted a fresh set of cards and rules. This is my own take with different rules and content: original programs, a netrunner setting and its own art direction. It is not affiliated with, endorsed by or derived from the original game's assets or code. It's not perfect, it was made with AI, so take for what it is : a few hours of fun gameplay provided for free.

How it was made

• Game design: direction and curation: a solo human designer on their spare time.
• Illustrations, comic pages and UI art: generated with ChatGPT.
• Code: written with Claude (Anthropic).

Credits

• Sound effects and music from Pixabay creators, listed in CREDITS.md.
• Fonts: Chakra Petch and Saira, SIL Open Font License 1.1 (licence texts in fonts/).

License

• Source code: PolyForm Noncommercial 1.0.0 — free for any non-commercial use, no commercial use.
• Illustrations, comic, UI and text: CC BY-NC 4.0, credit pizzattack.
• Third-party audio and fonts keep their own licences (see Credits).

The game is free to play and share; selling it or using it commercially is not allowed. Strictly speaking this is “source-available”, not OSI open source.