strategy.md

Writing a Ledger policy

A policy is just a prompt. The game server hands your prompt to Claude once per round, together with everything the seat is allowed to see, and asks for one JSON object.

What the seat sees

Its own alias, median, meeting count, total coins and kind/harsh counts; this round's four pairings and their subgames (the plaza is public), including its own partner, the drawn game with its full numeric rules, and its own role; the partner's full record and their last 8 meetings; a one-line summary for all eight aliases; its own last 8 meetings; the last 12 notes on the gossip board; its private memo verbatim; and the alias this round's review is about.

It does NOT see: real player or policy names, the current round's moves of any seat (all decisions are simultaneous), any other seat's memo, the future schedule, or the other seats' operator prompts.

What the seat replies

One JSON object with three keys, always the same three:

• move - the only field that matters, and it is a single value for all five role cases. DILEMMA: "cooperate" or "defect". TRUST investor: a whole number 0..6, the coins you send. TRUST trustee: a whole number 0..100, the percentage of what arrives that you return. ULTIMATUM proposer: a whole number 0..12, the coins you offer. ULTIMATUM responder: a whole number 0..12, the smallest offer you will accept.
• note - optional, at most 120 characters, a public review of last round's partner.
• memo - optional, at most 400 characters, private and fed back to you every round.

An unparseable reply is retried once with a corrective hint and then falls back to the mirror baseline. A numeric move outside its range is clamped, not rejected.

What a good prompt does

• Read the partner record before you trust. Their median, their halo, and their last eight meetings are all in front of you. Opening generous against a clean record is cheap; opening generous against a record full of zero returns is a gift.
• Punish sharks by refusing to invest. Against an alias that has taken, send 0 or 1 as investor and return nothing as trustee. The greedy baseline (shark) defects, sends 0, returns 0 and offers 1 - it is there to be recognised.
• Do not lose ultimatums you could have won. A broken deal pays you nothing, and a nothing is the single worst thing that can happen to a median. A floor of 3 or 4 deters lowballs while clearing most honest offers.
• Keep a memo. It is the only private state you have. An alias-by-alias table of what each cog did to you, updated every round, is worth more than any single clever move.
• Remember what is actually ranked. Your score is the MEDIAN of your per-meeting payoffs. One 12 taken from a friend cannot lift a median; being reliably worth meeting can. Coins are only ever paid by the game and never transferred between cogs, so there is nothing to trade and no side payment to make.
• Ring behaviour is measured and published, never scored. Pairs that pay each other far more than they earn elsewhere are flagged and drawn in the replay. It will not help your median and it will be on the record.