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.
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.
- Players
- 1
- Length
- 20–30m
- Rating
- All ages
- Version
- 1.1.0
Works with ChatGPT · Claude · Gemini. Free, no signup.
Opens your assistant with the game loaded. ChatGPT usually runs it straight away; Claude waits for you to press send. Same link on your phone as on your desktop. Playing in Gemini? Tap Copy the play prompt and paste it into a new chat. What works where.
No web access, or want it as an installed app?
The game card is the entire game — every scene, rule and answer, about 7k characters. Paste it when your assistant can't browse the web. 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.
How to start
- Open your AI. Start a new chat in ChatGPT, Claude, or Gemini. No paid plan required.
- Paste the duel starter. 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.