Sadari — Ladder Lottery Game

How Ladder Lottery Works

Sadari (사다리타기), also known as ladder lottery or Amidakuji in Japanese, is a simple yet mathematically fair method for random selection. It has been used across East Asia for centuries to make impartial decisions in groups.

Why Use Sadari?

Mathematically Fair

Each starting position maps to exactly one ending position through a one-to-one permutation. No outcome is duplicated, and no participant is left out. The randomness comes from the hidden rungs, making the selection process provably unbiased.

Transparent and Trustworthy

Unlike a simple random number generator, the ladder lottery is visual and traceable. Everyone can follow their path and verify the result. This transparency builds trust, especially in group settings where fairness matters.

Fun and Engaging

There is a real element of suspense as each person traces their path down the ladder. It turns an ordinary decision into a shared experience, which is why sadari is so popular for:

• Deciding who pays for lunch or dinner
• Assigning tasks or chores among roommates
• Picking teams for games or projects
• Party games and ice-breaker activities
• Office team-building exercises
• Classroom activity assignments

Frequently Asked Questions

What is Sadari (사다리타기)?

Sadari, which literally translates to "ladder riding" in Korean, is a traditional random selection method that has been used across East Asia for centuries. Players draw vertical lines side by side, then add random horizontal rungs between adjacent lines. Each participant starts at the top of one line and traces a path downward, switching direction whenever a horizontal rung is encountered. The position reached at the bottom determines the outcome. Sadari is culturally significant in Korea, Japan (where it is called Amidakuji), and China (known as ghost leg or 鬼脚图). It remains one of the most popular ways to make fair group decisions in Korean social settings, from deciding who picks up the dinner tab to assigning household chores. For a deeper dive into its history and cultural origins, read our complete guide to ladder lottery.

Is ladder lottery really fair?

Yes, ladder lottery is mathematically provably fair. Each starting position maps to exactly one unique ending position through a one-to-one permutation. No two players can land on the same result, and no result is left unassigned. As long as the horizontal rungs are placed randomly or hidden before players choose their starting positions, the outcome is unbiased and unpredictable. Research in combinatorics has confirmed that with a sufficient number of randomly placed rungs, the resulting permutation approaches a uniform random distribution, meaning every possible outcome is equally likely. To understand the math behind this fairness, explore our article on the mathematics of fairness in random selection.

How many players can use Sadari?

Sadari works with any number of players from 2 to practically unlimited, though it is most commonly used with 2 to 10 participants. For very small groups of 2 or 3, the ladder is simple and resolves quickly. For medium groups of 4 to 8, the game becomes more exciting because path intersections are harder to predict. For larger groups of 10 or more, a digital tool like ours is recommended since hand-drawn ladders become visually complex at that scale. Teachers have successfully used Sadari with entire classrooms of 30+ students using digital versions, and event organizers use it for groups of 50 or more in raffle-style drawings.

What is the difference between Sadari and Amidakuji?

Sadari (사다리타기) and Amidakuji (あみだくじ) are the same game known by different cultural names. Sadari is the Korean name meaning "ladder riding," while Amidakuji is the Japanese name, referencing the Amida Buddha whose radiant halo inspired the circular format of the original lottery. In China, the game is called "ghost leg" (鬼脚图) because the horizontal rungs resemble the legs of a ghostly figure. Despite the different names, the rules and mathematical principles are completely identical across all versions. The game likely originated in Japan during the Muromachi period (1336-1573) and spread to Korea and China through cultural exchange. Learn more about its rich history in our article on the history of Korean party games.

Can I use Sadari for more than just deciding who pays?

Absolutely. While deciding who pays for a meal is the most iconic and culturally recognized use of Sadari, the game is incredibly versatile for any scenario requiring fair random assignment. Common uses include assigning household chores among roommates, picking balanced teams for sports or games, organizing Secret Santa pairings at the office, determining presentation order in classrooms, selecting fantasy sports draft order, running raffle-style giveaways at events, and even serving as party ice-breakers. The transparent, visual nature of Sadari makes it especially useful when the group wants to see that the selection process was genuinely fair.

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