Ladder Game

About the ladder game (Amidakuji)

The ladder game — known as Amidakuji in Japan — is a classic way to randomly match participants to outcomes, such as assigning chores, picking who pays for lunch, or drawing prizes. Each participant picks a starting column, then follows the vertical line down, switching lanes whenever they hit a horizontal rung, until they reach their final result at the bottom.

How the random matching works

The tool generates a random set of horizontal rungs connecting adjacent vertical lines, making sure no two rungs touch the same column at the same row (which would create an ambiguous path). Because every path through the ladder never crosses itself and each rung swaps exactly two adjacent lanes, every participant is guaranteed to end up at exactly one distinct result — the randomness comes entirely from where the rungs are placed.

Frequently asked questions

Can two people end up with the same result?

No. The ladder structure guarantees a one-to-one mapping — every starting column leads to exactly one distinct ending column, so results are never duplicated or skipped.

Is the outcome really random, or can it be predicted?

The rungs are placed randomly each time you generate a new ladder, so the outcome can't be predicted in advance — including by whoever set up the ladder, since even they don't know which column leads where until the paths are revealed.

What's a typical use for this kind of game?

It's commonly used to assign random roles or outcomes fairly among a small group — for example, deciding who buys coffee, splitting up chores, or running a simple prize draw — without needing to shuffle physical cards or draw straws.