Iudex Arcanum

Iudex Arcanum is a rules judge, life counter, and AI deck builder for Magic and other trading card games — built for the real table, in real time. Stop pausing the game to argue. Ask the AI judge any rules question in plain English and get an instant answer that cites the exact Comprehensive Rules number, with a confidence level and a Dispute/Override flow for table calls. FREE — NO ACCOUNT NEEDED - 2–4 player life tracker with poison, commander damage, commander tax, and custom counters - Commander starts at 40; turn phases and a phase timer - The Stack: push spells & abilities and resolve them in order - Works at the table on your phone, even offline WITH AN ACCOUNT (pay-as-you-go — a few cents each, no subscription) - AI Rules Judge — cited rulings for any interaction - AI Deck Builder — describe a format, colors, budget and power tier; get a full legal decklist with a game plan - Card Lookup — plain-English search ("blue counterspell under two mana") - Camera Card Recognition — point your phone at a card; it's identified in about a second and logged - Card Check — estimate genuine vs. proxy and grade a card's condition No subscription. You only pay for the AI features you actually use, billed as small pay-as-you-go credit. New members get free credit to try everything. Supports Commander / EDH, Standard, Pioneer, Modern, Legacy, and Pauper. Unofficial & fan-made. Not affiliated with, endorsed, or sponsored by Wizards of the Coast.