Sea Salt & Paper

Use the 58-card base deck. Shuffle it facedown, reveal its top two cards to start two separate discard piles, and choose a random first player. Play clockwise, beginning without dealt starting hands.

First add one card to your hand: draw two from the deck, keep one, and discard the other faceup onto either discard pile, filling an empty pile if present; or take the top card of either discard pile. Normally you may not inspect a discard pile's contents.

Then you may play multiple Duo pairs, worth 1 card point each: two crabs search a chosen discard pile for one card without rearranging it; two boats grant another turn; two fish draw the top deck card; a swimmer and shark steal one random card from an opponent. Unplayed complete pairs score too, without effects.

Collectors score by quantity: 1-6 shells give 0, 2, 4, 6, 8, or 10 points; 1-5 octopuses give 0, 3, 6, 9, or 12; 1-3 penguins give 1, 3, or 5; and 1-2 sailors give 0 or 5.

Multipliers add points: the lighthouse gives 1 per boat, the shoal of fish 1 per fish, the penguin colony 2 per penguin, and the captain 3 per sailor. A multiplier card does not itself count as the type it rewards.

Each mermaid scores the number of cards in a different color group: use your largest color for the first, the largest remaining color for the second, and so on. Never count one color for two mermaids. Count cards in hand and in front of you; mermaids themselves are white.

At your turn's final step, at least 7 card points across your hand and played cards allow you to end the round. Reveal your hand and announce STOP or LAST CHANCE. With STOP, everyone reveals and immediately scores their card points, with no extra turns.

With LAST CHANCE, beginning with the player on your left and continuing clockwise, every opponent takes a final turn, adding a card and optionally playing Duos. After finishing, each reveals their hand, which becomes protected from attacks. The declarer receives no such extra turn.

Compare card points for the wager. If the declarer is at least tied with every opponent, they score their cards plus the size of their largest color group; opponents score only their own largest color groups. If anyone has strictly more card points, the declarer scores only their color bonus and every opponent scores their cards.

If the deck is empty at a turn's end, the round ends with no scoring. Otherwise accumulate round scores; if nobody reaches the target, reshuffle all cards and rebuild the discards, starting left of the previous round's ending player. Targets are 40/35/30 for 2/3/4 players. Highest total wins; ties favor the most points in the last round. Revealing all four mermaids immediately wins the whole game.