• Cards rank A (high) down to 2. There is also a Joker.
• Point cards are the A, K, Q, J and 10 of every suit: 20 points in a single deck (40 with two decks). Nothing else scores.
• Mighty — the A♠, or the A♦ when spades are trump. It beats everything and may be played at any time, even when you could follow suit. It still belongs to its suit: if that suit is led and the Mighty is the only card of it you hold, you must play it (or the Joker), and leading the Mighty asks for its suit.
• Joker — beats everything except the Mighty, even trump, and may be played at any time except to the first or last trick. So if you still hold it with two cards left, you must play it then (holding both Jokers with two decks: one on each of the last two tricks before the final one). Whoever leads it names the suit everyone must follow.
• Ripper — the 3♣, or the 3♠ when clubs are trump. Leading it demands the Joker: whoever holds the Joker must play it, and it becomes worthless for that trick. The only escape is to play the Mighty instead (not possible on the second-to-last trick, when the Joker must go anyway). It has no effect if the leader holds the Joker; with two decks it forces out every Joker in the other players' hands. It can't be led to the first trick.

• 5 players (standard): one deck plus the Joker, 10 cards each, 3 face down in the pickup (the "blind").
• 4 players: 2♥ and 2♣ removed, 12 cards each, 3 in the pickup. The bidder and one partner play against two.
• 6 players, 14 cards: a house variant — two decks with both Jokers, minus all the 2s and 4s and one 5♣ and one 5♥, 14 cards each, 4 in the pickup.
• 7 players (the best double-deck game): two decks without any 2♥ or 2♣ (102 cards), 14 cards each, 4 in the pickup.
• 8 players: the 7-player deck minus one 2♠ and one 2♦ (100 cards), 12 cards each, 4 in the pickup.
• Dealt no point cards and no Joker? That's a Yarborough: at your first turn to bid you may show it and the cards are redealt. Pass or bid instead, and the hand is played as usual.

• A bid is a number of points plus a trump suit or no-trump: 13–20 (25–40 with two decks). It's how many point cards you think you and your partner(s) can capture.
• Each bid must beat the last: more points, or the same number in no-trump over a suit. Suits don't outrank each other.
• The dealer bids first, then round clockwise. Pass skips just this turn — if someone bids after you, you can still come back in. Pass all takes you out of the auction.
• The high bid wins once everyone else still in has passed since it was made. If nobody bids at all, everyone gets one more turn starting with the dealer; if nobody bids then either, the cards are redealt.

• The bidder shows everyone the pickup, adds it to their hand and puts the same number of cards face down. Point cards put down count for the bidder's side.
• The bidder may then keep the contract or switch it, once: to another suit at +2 or to no-trump at +1 (+3 and +2 with two decks) — for example 15♣ can become 17 of another suit or 16 NT. A switch that would go past the maximum isn't possible.
• The bidder then calls a card that someone else holds (not one in their hand or put down) — usually the Mighty, or if they hold it, the Joker or a strong Ace. Whoever holds it is the secret partner; only the partner knows. Calling a card doesn't change its power.
• Two decks: the bidder calls two different cards and may call one they hold a single copy of (just not one they hold both copies of). For each, the first player other than the bidder to play a copy — or declare with it — becomes a partner. One player can end up as both partners.

• The bidder leads the first trick and may not lead trump there unless they hold nothing else, nor the Ripper. The winner of each trick leads the next.
• Follow the suit led if you can (the Mighty and the Joker are always allowed). If you can't, play anything.
• The trick goes to the Mighty; otherwise the Joker (unless it was ripped); otherwise the highest trump; otherwise the highest card of the suit led. With two identical cards (two decks), the first one played wins.
• A secret partner is revealed by playing the called card — or by declaring: after winning a trick, with point cards in front of them, they may announce themselves before leading the next. With two decks, a player can't become both partners through the same trick.
• Point cards won by defenders stay face up on the table; the bidder's side keeps theirs face down.
• Once every partner is known and the defenders have enough points to set the contract, the hand ends — the remaining tricks can't change the result.
• High contracts: on a contract of 17 or more (34 or more with two decks), the bidder may, just before leading, say "Partner, take this trick" — once a hand (twice with two decks). The partner doesn't have to obey.

• The bidder's side makes the contract by capturing at least the bid in points (the defenders need 21 minus the bid, or 41 minus the bid with two decks, to set it).
• A hand is worth the bid minus 12 (minus 24 with two decks): 13 is worth 1, 16 is worth 4. There is nothing extra for no-trump or for points beyond the bid.
• If it's made, each defender pays that value; the bidder and partner split the total 2:1 (2:1:1 with two partners). If it's set, the same amounts go the other way. Everyone's scores always add up to zero — for example, a made 16 with 5 players: defenders −4 each, bidder +8, partner +4.
• When the total doesn't split evenly (4 and 6 players, or one player holding both called cards), the largest amount that does is split and a leftover point goes to the bidder; two leftover points, one to each partner (to bidder and partner if there's only one); three, one to each.
• The partner deals the next hand (with two partners, the one nearest the bidder's left).

The bots follow the partnership conventions from the book, so you can read their play — and they read yours the same way. None of this is a rule; it's how bidder and partner talk without talking.

• Bidder, trick 1: lead an Ace outside trump (or the King of the Mighty's suit when the Mighty is on your side) to keep the lead. No such card? Call an Ace as partner and lead its suit — the card just below it if you have it, so the partner can hold the Ace back.
• Bidder holding the Joker, Mighty called: lead a losing point card on trick 1. It means "I have the Joker — don't rip. Mighty, take this and lead trump."
• Bidder, trick 2: lead the Joker (calling trump) if you have it. Leading anything else — a low trump, usually — says you don't, and asks the Mighty partner to win the trick and rip the Joker with the Ripper next. With no opening lead, a low non-point card on trick 1 asks the same thing a trick earlier.
• Calling a partner: no Mighty — call the Mighty. The Mighty and an opening lead — call the Joker. The Mighty but no opening lead — call an Ace in another suit and lead that suit.
• Keep the trump flowing: the bidder leads trump until the defenders are out. A Joker partner plays the Joker on the bidder's trump lead at trick 2, and any partner who wins the lead leads trump back.
• Don't collapse: if your side is already sure to win the trick, don't spend another winner on it — throw a low card, or a point card.
• Defending: attack the Mighty by leading its suit, and on a big contract pile points onto a trick your side might win, so the Mighty has to come out to stop it.
• Bidding: the bots bid on shape first — four or more trump and a lopsided hand — and aim for the level the book's guidelines support.
• Two decks (6–8 players): there's more to it — see the next section.

With two of every card, holding a called card doesn't make you a partner: the first player to play (or announce) a copy does. These are the book's double-deck conventions, as the bots play them.

Bidding

• Shape first: six or more trump in a lopsided hand (seven with 17 cards, five with 12). With 8 players a bidder also needs a Mighty or Joker of their own.
• Levels: 27–28 with one magic card (a Mighty or Joker), or strong trump and a strong side suit; 29–30 one magic card plus strength; 31 and up two magic cards and an opening lead; above 31 only holding a Mighty.
• Encouragement: a no-trump bid one above someone's bid says "I hold two magic cards for your trump" (and Aces or Kings, or long trump, besides). The bidder answers by bidding once more, and the encourager plays as a partner — anyone else holding the same called card leaves that slot to them.
• Calling: the Mighty and the Joker, even holding a copy of one — the other copies are the strongest partners there are.
• Burying: a point card that can't win goes in the pickup (its point is then the bidder's), not a low card. In no-trump, keep a card in every suit and a second card beside a lone Ace or King.

The bidder's leads

• Trick 1: an opening lead — Aces first, then the Ripper's suit (a defender who trumps it is out of that suit, so can't hold the Ripper), then the shortest suit.
• Losing point card on trick 1: only when holding the other Mighty. It says "you're my Mighty partner whatever happens — take this and lead trump, and don't rip."
• Trick 2: the Joker if you have it. Otherwise cash a sure winner first (the twin of the Ace that took trick 1), then make the rip request.
• Pull trump while anyone outside your side may still hold some — and stop once only your partners can, or you're just drawing theirs.

Holding a called card

• The lower card goes first: on a bidder's lead that isn't sure to win, the holder of the lower called card plays it (the Joker before the Mighty). The Mighty partner waits until the Joker partner has shown up — until then nobody else can beat the Joker.
• Don't lay off: play the called card when the bidder asks for it, however weak the rest of your hand. A partner who holds back leaves the bidder's plan in pieces ("partners, don't think").
• Then lead: sitting one or two seats after the bidder with exactly one other winner, cash it; otherwise lead trump — your highest with three or fewer, your lowest with more.
• The Mighty partner takes the bidder's losing point card with the Mighty, then leads trump.
• Holding both called cards: don't announce either until you know who holds the other copies — announcing the wrong one can lock out the other partner and leave you the only one. Once the bidder has played the other copy of one, you're certainly that partner. And once you're one partner, keep the other called card back so someone else can be the second.
• A spare Joker (not the called card) with a called card in hand: win a trick with it and announce yourself before someone with the other copy gets there first.

Rips and no-trump

• One rip can catch both Jokers — unless they're in one hand, or a Joker is held with a Mighty. Rip a Joker known to be with the other side; never while the called Joker is still to be played.
• No-trump partners lead back the suit the bidder bid in the auction (or led last), never a suit the bidder is out of, and play a high card under the bidder's sure winner ("unblocking") so the lead stays with them. Defenders lead the suits the bidder is out of.

The book suggests these for tables that agree on them. Pick them before the game starts (on the home screen, or in the lobby if you're the host).

• Switch to the maximum: after the pickup, the bidder may switch straight to 20 (40 with two decks) in any suit or no-trump, whatever the winning bid was.
• 4 players — no 13 contracts: a bid won at 13 is played at 14 in the same suit, or switched as usual (14 NT, or 15 in another suit). With 4 players a made 13 can't be split 2:1 between bidder and partner, so this keeps them apart.