Duels
Aqua Regia
The guild master's last elixir is four measures poured in a fixed order, sealed before you ever reached the bench; mix trial batches, read the assay, and reproduce it.
- Players
- 1
- Length
- 15–25 min
- Rated
- All ages
- Version
- 1.1.0
- Updated
Works with ChatGPT · Claude. Free, no signup.
Opens ChatGPT or Claude with the play prompt ready; press send if it hasn't started. Same link on your phone as on your desktop. Another app? Copy the play prompt into it. This game needs a chat that can open links: its answers stay in a sealed file on this site. What works where.
Want it as an installed app, or the card itself?
The game card is every rule of the game, about 10k characters, but not its answers: those stay in a sealed file on this site, so even pasted, Aqua Regia needs a chat that can open a link. Pasting the answers in yourself would spoil it. The Skill installs Aqua Regia into Claude on any plan: download it, then turn on code execution under Settings → Capabilities and add it at Customize → Skills → + → Upload a skill.
Aqua Regia is a free code-breaking deduction game you play inside ChatGPT or Claude. Mastermind-style code-breaking: find a sealed four-part formula in ten tries from the two counts the AI reads off each trial mix. Solo, 15–25 min a run. No signup and nothing to install: open it in your assistant, or paste the play prompt into any chat that can open links.
How to start
- Open it in your AI. Tap Open in ChatGPT or Open in Claude, and press send, or paste the play prompt into any assistant that can open links. No paid plan required.
- The game loads. The formula was sealed with a SHA-256 hash before release and is not printed on the card: the AI fetches it from this site, so play in a chat that can open links. It reads you the hash before your first batch.
- Mix and read. Name four essences in order. The AI answers with two counts: SET for a right essence in the right place, HAZE for a right essence in the wrong place. Use them to close in on the formula.
- Verify the seal. After the game, paste the revealed answer into aigamecards.com/verify, which recomputes the hash in your browser.
Questions
- What stops the AI from changing the formula when I get close?
- The formula is fixed before play and committed with a SHA-256 hash the AI shows you before your first batch. Every SET/HAZE count is read from that locked formula, and you rebuild the hash from the revealed answer afterwards to prove nothing moved.
- Is the AI actually any good at this?
- Yes. It only checks each batch against one fixed formula using one fixed counting rule: SET is the measures right in both essence and rank, HAZE is the measures of a right essence in a wrong rank. It follows the same procedure every time and has nothing to improvise.
- How long is a game, and how hard is it?
- About 15 to 25 minutes. The formula is four measures drawn from six essences with repeats allowed, so 1296 orders are possible, and you get 10 batches to reproduce it. It is the classic Mastermind problem — four slots, six symbols, repeats allowed — re-poured as an alchemist's bench: read the two counts, rule out orders, and close in.
- Do I need an account, and why must the chat open a link?
- No account beyond the chat app you already use, no paid plan. The link is the point: the formula is not printed on this card, because if it were, the first thing you read would be the answer. The AI, playing the Assay-Master, opens the sealed reveal from this site as it loads, holds it out of your sight, and assays every batch against it. So run this one in a chat that can open links (the compatibility page shows which apps do) and never paste the reveal in yourself, because that is the answer, on your screen. Checking the seal afterwards is a single paste at aigamecards.com/verify, recomputed in your browser.