Deck composition (48 cards, 4 for each of 12 months)
Hwatu consists of 48 cards in total: 4 cards for each month from January to December, each decorated with a seasonal image. The 4 cards for each month are divided by role into gwang (bright/light cards), yeolkkeut (animal/junk cards), tti (ribbon cards), and pi (chaff/junk cards), and the specific combination differs slightly from month to month. For example, January, March, August, November, and December each include one gwang card, while other months may consist only of yeolkkeut, tti, or pi cards. Go-Stop is played by using these 48 cards to match and collect cards laid out on the table with cards in one's hand.
Gwang β the highest-value cards
The five gwang cards β January (pine and crane), March (cherry blossoms), August (full moon over an empty mountain), November (paulownia), and December (rain gwang) β have the greatest impact on the outcome of the game. Collecting three gwang cards is called "3-gwang," four is "4-gwang," and all five together is called "5-gwang" (ogwang), each earning a set base score. Many groups apply a house rule where the score changes under a "rain" condition (such as a 3-gwang that includes the December rain-gwang card), so it's best to agree on the specific rules with your group beforehand.
Yeolkkeut β cards featuring animals or objects
Each month has a yeolkkeut card featuring an animal or object; if you collect five or more, any cards beyond the fifth count toward your score. Among the yeolkkeut cards, collecting the three cards featuring birds earns a separate combination called "godori," worth extra points. A single yeolkkeut card carries no base score on its own, but the common rule is that once you collect more than five, each additional card (starting from the sixth) is worth one point.
Tti β the colored ribbon cards
These are divided into three colors: hongdan (red ribbons), cheongdan (blue ribbons), and chodan (ribbons with writing on them), and collecting all three cards of the same color forms a scoring combination. Collecting all three cards of hongdan, cheongdan, or chodan each counts as a separate combination worth points. As with yeolkkeut, collecting more than five ribbons of the same color often means the extra cards are counted as bonus points.
Pi β the basic scoring unit
Pi cards are all the remaining cards that don't belong to gwang, yeolkkeut, or tti; they are the most basic scoring unit, with 10 pi cards needed to earn 1 point. If a "double pi" card (a special card worth the value of two regular pi cards) is included, it is counted as two cards when tallying your pi total. Because the number of pi cards collected by the end of the game has a major impact on the final score, players who aren't able to pursue gwang or other combinations often adopt a strategy of collecting as many pi cards as possible instead.
Basic gameplay (usually 2β3 players)
Cards are laid out face-up on the table, and players search for cards from the same month among their hand to match and collect. On your turn, you play one card from your hand; if a card from the same month is on the table, you take both cards as a matched pair. If there's no match, the card you played is simply left on the table. Next, a card is flipped from the draw pile and matched the same way. Combinations of gwang, yeolkkeut, tti, and pi are formed from the cards collected through this process, and these combinations determine your score.
What "Go" and "Stop" mean
Once a player reaches a minimum score first, they can choose whether to keep playing ("go") or end the round here ("stop"). Calling "go" and continuing lets you aim for a bigger score, but you also risk a loss if your opponent scores first. The more times a player calls "go" (double-go, triple-go, and so on), the higher the score multiplier becomes if they ultimately win, and this tension is considered one of the core thrills of Go-Stop.
Special situations: shaking, ttadak, and bombs
Holding three cards from the same month in your hand lets you declare a "shake" (heundeulgi), and there are also special situations in which multiple cards are collected at once, both of which affect scoring. Shaking means showing your three same-month cards in advance so that a later match from that month can be handled to your advantage, while a "bomb" refers to a situation where two cards from the same month are already on the table and you use your remaining two matching cards from your hand to sweep up all four cards at once. These special rules can double the score and are treated as important by experienced players, but whether they apply β and the exact multiplier β can differ from group to group.
Penalty terms like pibak, gwangbak, and meongteonggeuri
Players who fail to score often face a penalty that doubles the final amount they owe under certain conditions. For example, if a player finishes the game having collected fewer than a set number of pi cards, they are hit with "pibak" (pi penalty); if a player collects no gwang at all while their opponent scores with gwang, they are hit with "gwangbak" (gwang penalty). These penalty terms and their multipliers vary considerably by region and group, so if you're playing with new people, briefly agreeing on which rules to apply beforehand helps avoid disputes.