What is the ladder game?
The ladder game — known as Ghost Leg in English, Amidakuji in Japan, and Sadaritagi in Korea — is an old way of drawing lots that pairs participants with outcomes one to one, using a ladder-shaped diagram of vertical lines joined by randomly placed horizontal rungs. Starting from a participant’s spot at the top, you follow the line down, and every time you reach a rung you cross over to the neighboring line, until you arrive at one of the outcomes at the bottom.
How to use it
- Enter one participant name per line on the left (2 to 12 people).
- Enter one outcome per line on the right (prizes, chores, roles — anything). If you enter fewer outcomes than participants, the remaining spots are blank; you can’t enter more outcomes than participants.
- Set the number of rungs. A default based on the number of participants is already filled in, so you can leave it as is.
- Click “Create ladder”. The outcomes at the bottom are shuffled, and the middle of the ladder, where the rungs are, is covered so nobody can trace the paths in advance.
- If you like, click “Shuffle ladder” (same number of rungs, new positions and outcome order), “Shuffle participants” (reorder the top), or “Shuffle outcomes” (reorder the bottom).
- Click “Show results” to lift the cover and see the list of who got what. Click a participant’s name to draw their path in color, or click “Show all paths” to draw every path at once.
How is it kept fair?
Rung positions and shuffle orders are chosen with cryptographically secure randomness (crypto.getRandomValues), computed entirely in your browser and never sent anywhere. No two rungs are placed in neighboring gaps at the same height, so every path is unambiguous, and every gap between two vertical lines gets at least one rung, so the ladder never splits apart. Each rung simply swaps two neighboring spots, so no matter how many rungs a path crosses, the result is always a one-to-one mapping (a permutation). The rungs aren’t drawn on screen until you click “Show results”, so there’s no peeking under the cover.
Each time a ladder is made (“Create ladder” or “Shuffle ladder”), the order of the outcomes at the bottom is shuffled too, so every pairing of participants and outcomes is equally likely, whatever the number of rungs.
Example uses
Deciding who pays the bill after a group meal, setting an order before splitting into teams, assigning roles for a group project, or picking who handles the trip expenses. Enter just a few prizes and leave the rest blank to draw a handful of winners from a larger group.
Things to know
Refreshing the page or clicking “Create ladder” or any shuffle button discards the current ladder and builds a new, covered one. If you need to remember a result, click “Show results” and take a screenshot or write it down. Nothing you enter ever leaves your browser — all the computation happens locally.