DECOHERENCE — RULES (as implemented at decoherence.vaguespac.es) A two-player card game about quantum mechanics. Twelve words, sixty sentences. 1. THE WORDS Verbs (phenomenon): tapped (tunneling), verved (energy), boo'd (measurement), twigged (entanglement), riffed (interference) Qualifiers (outcome): up (spin up), down (spin down), through (a pass), out (decay) Nouns (particle): kiki — fermion, size 3 bouba — boson, size 2, +1 per other bouba you have in the same spin lulu — carrier, size 2; each lulu you have on the table adds 1 to verved through A sentence is one verb, one qualifier and one noun, in that order. "Riffed up bouba." 2. DECK AND SETUP Each player has 30 cards: 10 verbs, 10 qualifiers, 10 nouns, no more than 4 copies of any word. Each player starts at 10 verve. Verve is coherence, and it is also your life. Verve is public. Coin flip for who goes first. Opening hands are seeded: draw until you hold a verb, a qualifier and a noun, shuffle the rest back, then draw 2 more (5 cards, at least one complete sentence). 3. THE TABLE Open chains: sentences under construction (a verb alone, or a verb and a qualifier). Face-up. At most 3. States: finished sentences whose qualifier was up or down. A state has a spin, a noun and a size. Bare particles: what a through or out sentence leaves. Just the noun, no spin. Nouns are played face-down. A noun on the table is hidden (opponent hasn't seen it), known (seen, never measured) or measured (revealed by boo'd). 4. TURN 1. Draw one card. If your deck is empty, you lose. 2. Play any number of cards, one at a time, in chain order: a verb starts a chain; a qualifier joins a chain holding only a verb; a noun joins a chain holding a verb and a qualifier, and the chain resolves immediately. You may pass at any point. Closing: you may put your noun on an opponent's chain that holds a verb and a qualifier. Pay verve equal to the noun's size (kiki 3, bouba 2, lulu 2). The sentence resolves as theirs, with your noun; the result belongs to them and is known, not hidden. You must be able to pay. 3. Discard down to 7 cards. 4. Leak: lose 1 verve per open chain. Verved up adds 1; verved down sets it to 0. At 0 you lose. 5. RESOLVING N is the noun's size at resolution. Sentences that use N flip the noun face-up (known): verved up, verved through, verved out, tapped through, tapped out, riffed up, riffed down. Up/down leaves a state; through/out leaves a bare particle. Exceptions: a riffed up/down that cancels leaves nothing; riffed out leaves nothing; twigged through that links leaves a spinless linked state. If a sentence has no legal target it has no effect, but what it leaves behind is still left behind. tapped up/down: Pay 1. Choose an opponent's state; its spin becomes up/down. An entangled partner takes the opposite spin. tapped through: Pay 1. Coin flip. Heads: the opponent loses N verve. tapped out: Pay 1. Choose an opponent's non-entangled state or bare particle. It is revealed (known). If its size is N or less, it is discarded. verved up: Gain N. Your leak this turn is 1 higher. verved down: Gain 1. Your leak this turn is 0. verved through: Gain N, plus 1 per lulu you have on the table. verved out: The opponent loses N. You lose 1. boo'd up/down: Choose an opponent's hidden, non-entangled state or bare particle. It is measured and its spin becomes up/down. boo'd through: Sweep: every hidden, non-entangled bare particle of the opponent's is measured. If none, measure one hidden, non-entangled state instead, spin unchanged. boo'd out: Choose an opponent's hidden, non-entangled state or bare particle. Reveal and discard it. twigged up/down: Choose one of your own states or bare particles, neither measured nor entangled. Link this state to it. This state is up/down; the partner takes the opposite spin. twigged through: Choose an opponent's state or bare particle, neither measured nor entangled. Link this sentence's result (a spinless state) to it. twigged out: As twigged up, but the link is fatal. riffed up/down: Choose an opponent's state with a spin. Same spin: both grow by N (permanently). Opposite spin: both are discarded; this sentence leaves nothing. riffed through: Nothing happens. A bare particle is left. riffed out: Choose any opponent's state or bare particle. Discard it and this noun. Nothing is left. Tapped costs its 1 verve even with no target, a failed coin, or a target too big to decay. 6. ENTANGLEMENT A link joins exactly two things. Neither can be measured (boo'd), examined (tapped out) or chosen by twigged again while the link holds. If both halves have spins they are always opposite: when one is pushed or collapsed, the other takes the opposite spin. A twigged-through link has a spinless half. A link breaks when either half leaves the table. If the link was fatal, the other half is discarded too. Otherwise the survivor goes dark: it becomes a hidden bare particle (spin removed). 7. WINNING Decoherence: a player at 0 or less verve loses at once. A player who must draw from an empty deck loses at once. Made classical: at the start of your turn, if the opponent has no hidden nouns, no live links and no open chains, they lose. An empty board counts. Not checked on either player's first turn. If both would lose at once, the one with more hidden nouns on the table wins; equal is a draw. 8. EDGE CASES Exclusion: you can't hold two kikis in the same spin. A kiki that would enter a spin you already hold a kiki in takes the other spin; if you hold both, a new kiki is discarded on arrival with no effect. Exclusion applies per holder; pushing an opponent's kiki uses their piles. Bunching: bouba's size counts other boubas you hold in the same spin at the moment it is checked. Verved through with no lulus gains N. Verved out at 1 verve costs your last point; you lose. Discarded cards, including the verb and qualifier of a resolved chain, are face-up and public.