IUDEX ARCANUM
Sign in

The free rules judge & deck builder
for trading card games

A free companion for Magic: The Gathering and other trading card games. Track life, phases, counters and the stack at the table — no sign-up. Then sign in to ask an AI judge for instant rule rulings, look up cards, build decks, and check a card's authenticity and condition.

No account needed to track a game. Add to your phone's home screen for a full-screen app.

What you can do

🎯 Life & score tracker Free

Two-player life totals, poison, commander damage, custom counters, turn phases and a phase timer — a clean digital scorepad for any trading card game.

📚 The Stack & turn tracker Free

Push spells and abilities onto the stack, resolve in order, and step through every phase of the turn. Camera support to point at the board.

⚖️ AI rules judge Account

Ask any rules question and get an instant ruling with cited rule numbers, confidence level, and a Dispute/Override flow for table calls.

🔍 Card lookup Account

Look up any card's oracle text, format legality, rarity, and official rulings in seconds.

🛠️ AI deck builder Account

Describe a format, colors, budget and playstyle — or use your saved collection — and get a full, legal decklist with strategy and a sideboard.

🪪 Card authenticity & condition Account

Snap a photo to estimate whether a card is genuine or a proxy, and grade its condition on the TCGplayer scale — handy for trading outside official stores.

Built for every format

The rules judge and deck builder understand the major constructed and singleton formats:

Commander / EDHStandardPioneerModernLegacyPauper
📲 Install it like an app. On iPhone: open in Safari → Share → Add to Home Screen. On Android: open in Chrome → menu → Install app. It runs full-screen and works at the table.