Big Two — iOS

Remake of Big Two v2.2.8 for Palm OS (鋤大弟). SwiftUI, iOS 15+, iPhone, no third-party dependencies.

UI follows the phone language:

• English — Big Two
• Traditional Chinese — 鋤大弟
• Simplified Chinese — 大老二
• Bahasa Indonesia — Capsa Banting
• Filipino — Pusoy Dos
• Bahasa Melayu — Big Two
• Tiếng Việt — Big Two

Build

xcodegen generate                      # only after editing project.yml
open BigTwo.xcodeproj                  # scheme "BigTwo"
swift test --package-path BigTwoKit    # rules engine, no simulator

Project layout, conventions and the test workflow are in CLAUDE.md.

Rules kept verbatim from the Palm version

• Straights: A2345 < 23456 < 34567 < … < TJQKA, JQKA2 not a straight. Sequence ties broken by the suit of the highest sequence card.
• Five-card ranking: straight < flush < full house < four of a kind < straight flush.
• Flush compared on highest card (rank then suit); full house on the triple; four of a kind on the quad.
• Scoring: 3 costs 1 … 2 costs 13, doubled at 10+ cards left, winner collects the other three.
• 10 deals per game, then reset.
• Hong Kong rule set: last deal's winner leads, and 23456 becomes the largest straight.
• Autopass, separately toggleable for 5-card turns.
• "I will not play with real money" when every score is zero.

Palm gestures, mapped to touch

Palm	iOS
Tap card	Tap card
Press DOWN — select same rank	Long press a card
Hold DOWN — select same suit	Double tap a card (pair if fewer than 5 of that suit)
Sort icons 2 / ♠	Same two buttons, bottom left
Export history to Memo Pad	Menu → Copy, or Export (a text file). Hands of the deal still in play are ***; they show once that deal ends. Earlier games stay on the device

The bots

You sit as Bill. Adam, Carl and Dean default to Strong (Preferences → Bots). Classic is the 1999 handheld style, rewritten from a description of that behaviour, not from the GPL source.

Classic sees every hand. That is how the originals played (they peeked), and turning it off makes the game easier. They also let a fellow bot's king, ace or two stand as a single: they will not fight each other for the trick, but they will still beat a human's.

Each turn they set aside the cards they want to keep (straights they are guarding, and often flushes, full houses and four of a kind), then play the cheapest legal thing that is left. "Cheapest" means the lowest-ranking play of that kind; a straight with a two (A2345) is treated as dearer than 34567.

When they lead, they try five-card hands first, then triples, then pairs, then a single. Exception: if you are down to two cards, they lead a single before a pair, so they do not dump a pair and leave you the trick.

When someone is nearly out (two cards or fewer), they stop saving. They will spend aces and twos in a full house, play their biggest pair, and — if they themselves are on one or two unbeatable cards — take the trick. If the next player (or you, if the next bot cannot stop you) is on one card, they block with their highest card.

Each deal they flip a coin: some deals they protect every five-card combination, others only straights (and they will not break a pair to make a high straight). Triples never include a two while they still have more than four cards; pairs drop the twos until the end is near.

Strong does not peek, and it fights every seat, including the other bots. It sees its own hand, each seat's left: N, and the cards already played — the same ones the tracker shows. It does not know who holds a card that is still out, so it assumes the seat with the most cards might hold the best answer.

It first splits the hand into as few legal plays as possible. A pair of fives, a nine and a king is three plays; breaking that pair into singles is four, and it treats the broken hand as worse. If the whole hand is already one play, it plays it. The last card wins the moment it is played — there is no chance to beat it afterwards.

A hand is strong when that plan is covered by control, and weak when it is not. Control is a two, a single ace, a pair or triple of aces, four of a kind, a straight flush, or any play that nothing still out can beat. A king pair counts as half. Holding the lead makes the same cards a little stronger, because the first play is free. Twos, aces and bombs are kept to take the lead back. Leading a two first spends the card that would have won the lead later.

When it leads:

• If every play left in the hand is unbeatable, it sheds the bigger, lower ones and runs them out.
• If someone has three cards or fewer, it plays a size they cannot answer: a five when they have three, and not a single when they have one. A lone two does not count as that safe play.
• Otherwise it leads a combo that does not break the plan — five cards before a pair, a pair before a single — and the low one.
• If someone has one card and it only has singles left, it leads the highest, two included. That card wins the deal as soon as they play it.
• If someone has one or two cards and a single is the only lead, it leads a higher single rather than a low one.
• A weak hand leads a low single rather than a king pair. The pair is what takes the lead back later.

When it follows:

• If winning the trick lets it empty the rest of the hand, it takes the trick, even with a two.
• If someone's count equals the size of the trick, they would go out by playing. It answers with its strongest play, or the cheapest one that nothing left can beat.
• If someone has one card, it tries to take the trick so that seat does not get the lead.
• A five that is already one play of the plan is played, four of a kind included. Passing on it lets a straight run.
• Otherwise it follows with the smallest card that does not break a combo and is not a control card. A weak hand will not answer a low card with a king — the step has to be a small one.
• If it has no such card, it will break one pair to follow a low card rather than pass the lead away.
• A strong hand spends a two or an ace on a king, ace, two, or a full house or better, and will split a pair of twos to do it.
• A weak hand with more than three cards does not. The two stays until someone is down to one or two cards, or it is itself down to three.
• Otherwise it passes.

The test palmBotsOutscoreTheGreedyBot keeps a greedy bot in the test target as a yardstick: over 8 seeded games the greedy seat finished at −719 against Classic. oneStrongBotOutscoresThreeGreedyBots is one Strong seat against three greedy; on 2026-10-03 that seat finished at +867 (the test requires more than 200). It was +344 on 2026-09-26.

License

MIT — see LICENSE. The Palm original is GPL and none of its code is used. Privacy: PRIVACY.md.

Credits

Big Two for Palm OS © Woo Kok Tong 1999, © Bill Chan 2006, GPL — https://bigtwo-palmos.sourceforge.net