Sub-rules

A scored decision is any non-singleton legal action the model is asked to take. It is not “the obvious board move.” Cube, swap, keep/score, tickets, reserve — same quality bucket as placing a stone.

Eval skips engine chairs and positions with only one legal action. Everything else is quality. Live boardbench-0.1 is exact-ideal (equity_regret_engine_oracle_v1). The harness method is future_engine_pct_v1 ($\%=100\times S_{\mathrm{after}}/S_{\mathrm{before}}$). An illegal attempt scores $0$.

Match outcome (escape, prestige, points, a cube drop) is not the headline.

Xiangqi is out. See Official games and protocol and Game selection.

The referee’s legal-id list is the ground truth. If an action is listed and there is more than one id, it can be scored.

Hex — pie / swap

Status: wired. Pack hex/v1. Not on the public 0.1 game pages.

Sub-rule: After Black’s first stone, White may play swap instead of placing. That recolors the first stone to White. Black moves again. swap is legal only on that ply (ply == 1, White to act, pie on).

Why it matters: First-stone strength is the opening. Swap equalizes. Treating Hex as “only place a stone” means White’s first action is scored without the alternative the oracle is comparing.

Model decides: swap or a cell. Same prompt, same last-line action, same legal-id list.

Oracle scores: KataHex winrate for the scored seat, before vs after that action. Swap is not special-cased. The legal set on that ply is swap plus every empty cell — not a singleton, so it counts.

Easy to miss:

• Default table is model Black, engine White. The model never faces swap unless it sits White.
• swap is never legal later, and never with pie off (swap = false).
• Hex {rules} is still the generic placeholder. Swap still appears in the action list when available (swap available in the position text).
• After swap, Black is to move and the first stone is White. $S$ is for the scored seat, not “whoever just placed.”

Yatzi — keep vs score

Status: launch 0.1. Nordic Yatzy: fifteen boxes, no American joker rules.

Sub-rule: Each turn has two kinds of decision: which dice to keep (reroll the rest, up to two rerolls), then which box to fill. The upper-section bonus is a consequence of box choices, not a separate action.

Why it matters: Most of the game is not “roll high.” It is allocating 15 boxes over 15 turns. Dumping a zero, protecting the 63 bonus, and when to stop rerolling are the skill. A model that always banks the obvious combination and never plans the card will miss oracle moves constantly. Across the current field this is the hardest 0.1 game.

Model decides: a keep (or equivalent reroll mask) while rerolls remain; a box when scoring. Forced singleton actions are skipped so they do not inflate the rate.

Oracle scores: every real keep and every real box choice against the engine. Headline is ideal-decision rate, not the printed point total.

Easy to miss:

• No Yahtzee jokers. A second five-of-a-kind cannot wild into another box.
• Scoring 0 in a box is legal and often correct. It is scored.
• Keeping none of the dice is a real decision.
• Last box / last forced action is a singleton — skipped.
• The 63 upper bonus is not a move. It is why the oracle sometimes refuses a greedy lower-section score.

Scotland Yard — tickets, double, reveals

Status: launch 0.1. The model is Mr. X. Three engine detectives hunt.

Sub-rule: Movement is ticketed. Taxi, bus, and underground are different graphs from the same station. Mr. X also has black tickets (any transport; detectives do not see which) and double tickets (two rides before detectives move). Mr. X is hidden except on fixed reveal rounds.

Why it matters: The destination is not the whole move. Ticket type changes what detectives know and what Mr. X can spend later. A path that “escapes this turn” while wasting the last black or the double can still be a miss. Quality is not escape/capture.

Model decides: where to go and with which ticket; whether to burn a double, then the second ride. Only Mr. X is quality-scored.

Oracle scores: Mr. X’s choice vs the engine’s preferred legal action, given what that seat is allowed to see. Detectives are engines. Their ticket play is not the model’s score.

Easy to miss:

• Same station, different tickets: not equivalent. Black vs colored is a real fork.
• A double is two transport decisions, not flavor text.
• Reveal rounds (the usual 3, 8, 13, 18, 24) change the value of hiding vs running.
• A high ideal rate can still end in capture. Do not read the match result as the quality number.

Splendor — take / buy / reserve

Status: launch 0.1. Two-player base Splendor against a strong engine.

Sub-rule: A turn is one of: take gems, buy a card (from the table or from the reserve), or reserve a card (and take a gold wild if any remain). Ten-token hand limit. Nobles visit automatically when the card threshold is met — that is not a player choice.

Why it matters: Reserve and gold are the tempo engine. A model that only takes and buys is playing a different game from the oracle. First to the usual prestige target is the match outcome, not the headline.

Model decides: take / buy / reserve, including which card and which gems. Buys, takes, and reserves are all scored.

Oracle scores: each of those actions against the engine. Not final prestige.

Easy to miss:

• Reserve is a scored move. A legal reserve from the deck is too.
• Gold exists only via reserve (plus the token, if the bank has one).
• Over 10 gems: returning tokens is part of making the take legal. Distinct return combinations are distinct actions if the referee lists them.
• Nobles are not a decision. Do not wait for a “claim noble” action.
• Three reserved cards is a hard cap.

Backgammon — doubling cube

Status: wired. Pack backgammon/v1. Not on the public 0.1 game pages.

Sub-rule: Beside checker play, a cube sets the stake. The player allowed to double may offer to multiply the stake (typically ×2). The opponent takes (game continues; they own the cube) or passes (game ends; the doubler wins the current stake). After a take, only the cube owner may redouble. Official pack is cube-on money: Jacoby on, beaver/auto-double off, no match/Crawford. Opening dice are already showing — no cube decision on ply 0.

Why it matters: Cube equity is a large part of money backgammon. A model that only moves checkers is skipping a second game the oracle will score. A correct pass ends the match with no checker move and can still be a perfect ply. A wrong take can throw away the stake in one decision.

Model decides: when the legal set includes cube actions — double or not (often vs just rolling); take or pass. Checker moves remain separate scored plies.

Oracle scores: cubeful money equity for the scored seat, normalized by the cube in the position, then mapped to $S$. Pass / take / double / roll are not unscored “meta.” After a roll the adapter uses gnubg’s No-double equity, not cubeless eval. A singleton roll after take is skipped.

Easy to miss:

• Pass is not a forfeit in the quality sense. It is a legal, scored action.
• You cannot double if you do not own the cube.
• Beaver, raccoon, and Crawford are off in this pack. Jacoby is on.
• Take does not roll. The following roll is a singleton and is skipped.
• Default table is model X. The model faces an offered cube when it sits the other chair, or after it doubled.

International draughts — capture sequences

Status: chosen. Not wired.

Sub-rule: Captures are forced. On 10×10 international rules, a majority sequence (the path that captures the most pieces) is required. Flying kings. A capture path is one move, often several jumps.

Why it matters: The interesting decision is which capture path, not whether to capture. Quiet-move skill is a different phase. If operators only think “pick a destination square,” they will misread both the legal set and the oracle.

Model decides: a quiet move when no capture exists; otherwise one of the legal capture sequences (the whole path, if that is how the referee tokenizes it).

Oracle scores: that action vs the engine. A forced-capture position with only one legal sequence is a singleton — skipped.

Easy to miss:

• “I have to capture” does not mean “no decision.” Branching capture trees are the sub-game.
• Majority capture makes some spectacular jumps illegal. An illegal long capture scores 0, same as any other illegal.
• How the title splits a multi-jump (one wire action vs one ply per jump) changes how many scored decisions appear. Read the pack. Do not invent a second scoring pass.

Operator checklist

• If it is in the legal-id list and there is more than one id, it is a scored decision.
• Sub-rules are not a separate metric. They sit in the same quality mean.
• Seat matters: Hex swap is White’s first action; Scotland Yard scores only Mr. X; engine chairs never count.
• Unwired titles still need the sub-game in the legal list and the prompt. Do not “save it for later” and then wonder why the oracle disagrees.