Duels
Deadreckoning
Four hulls lie somewhere on an eight-by-eight sea, berthed and hashed before your first salvo; you have nothing but the misses to find them by.
- Players
- 1
- Length
- 20–30m
- Ages
- All ages
- Version
- 1.2.0
- Updated
Works with ChatGPT · Claude · Gemini. 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.
No web access, or want it as an installed app?
The game card is every rule of the game, about 8k characters, but not its answers: those stay in a sealed file on this site, so even pasted, Deadreckoning needs a chat that can open a link. Pasting the answers in yourself would spoil it. The Skill installs Deadreckoning into Claude on any plan: download it, then turn on code execution under Settings → Capabilities and add it at Customize → Skills → + → Upload a skill.
Deadreckoning is a free naval strategy game you play inside ChatGPT, Claude, or Gemini. A hidden-fleet naval duel against an AI whose layout is sealed and verifiable. Solo, 20–30m a run. No signup and no app — open it in your assistant, or paste the play prompt anywhere else.
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 berth is already sealed under a SHA-256 hash; the AI reads you that commitment before your first salvo.
- Call your shots. Call a cell, listen to the water, and let the misses draw the shape of what's out there.
- Verify the seal. Hash the revealed berth against the commitment the AI read you at the rail. Ten cells, named before your first shot — every miss you took was the truth about where they weren't.
Questions
- Could the AI just slide a ship out from under my salvo?
- It has nowhere to slide it to. Four hulls, ten cells, berthed and hashed with SHA-256 before your first shot, and the AI reads you that hash at the rail — every hit and miss after that is resolved off a fixed grid. When the last hull goes down you hash the revealed berth and watch it match.
- How long does a duel take?
- Twenty to thirty minutes for a single duel. You call one cell at a time and the sea is cleared when the fourth hull goes down. Long enough to plan a real hunt, short enough to finish in one sitting.
- Can I play it on my phone?
- Yes. It runs entirely in a chat with ChatGPT, Claude, or Gemini, so any device that opens one of those works. There is no app to install and no account beyond the chat itself.
- Is it suitable for kids?
- Yes, it is rated all ages. The theme is naval strategy, deduction and grid tactics with no graphic content. Younger players get a clean logic duel, and the sealed-layout twist adds a fairness angle older players tend to appreciate.