What is the ladder game?
It is a way of drawing lots. You draw one vertical line per person and put horizontal rungs between the lines. Starting at the top, you follow a line down and cross to the neighboring line every time you meet a rung. Whatever is written where you reach the bottom is your result. It is the same game that is called sadari-tagi (사다리타기) in Korea, Amidakuji (あみだくじ) in Japan and Ghost leg in English. However the rungs are placed, only one person ever arrives at each spot.
How to use it
When the page opens, a ladder made from 4 sample names and 2 sample outcomes is already there. Delete the samples and type in your own.
- In the “Participants (one per line, 2–12 people)” box, enter one name per line.
- In the “Outcomes (one per line)” box, enter prizes, forfeits, roles or anything else, one per line. You can’t have more outcomes than participants. If you have fewer, the leftover spots become “Blank”.
- You can leave “Number of rungs” as it is. The section below explains how to choose it.
- Click “Create ladder” to build a new ladder. The participant names appear along the top and the outcomes, in shuffled order, along the bottom. The middle, where the rungs are, is hidden behind a cover.
- Click “Show results” to lift the cover and reveal the rungs. Each participant’s outcome is listed under “Results” below the ladder.
- Click a participant’s name above the ladder to draw that person’s path as a colored line. Click it again to remove it. “Show all paths” draws every path at once, and the same button then becomes “Clear paths”.
Three buttons shuffle a ladder that has already been built. Each of them covers the ladder again.
| Button | What changes | What stays |
|---|---|---|
| Shuffle ladder | Rung positions, order of outcomes at the bottom | Number of rungs, order of participants |
| Shuffle participants | Order of participants at the top | Rungs, order of outcomes |
| Shuffle outcomes | Order of outcomes at the bottom (including blank spots) | Rungs, order of participants |
Choosing the number of rungs
The allowed range depends on the number of participants and is shown next to the box, for example “3–18 rungs”. The minimum is the number of gaps between vertical lines (participants - 1). The maximum is 6 times that, or 10 if 6 times comes to less than 10. The starting value is 3 times the number of gaps, or 5 if 3 times comes to less than 5.
| Participants | Allowed range | Starting value |
|---|---|---|
| 2 | 1–10 rungs | 5 |
| 4 | 3–18 rungs | 9 |
| 6 | 5–30 rungs | 15 |
| 8 | 7–42 rungs | 21 |
| 12 | 11–66 rungs | 33 |
Until you edit this box yourself, the starting value follows along whenever the number of participants changes. Once you have edited it, your number stays put, so if you add or remove a lot of participants, check that it is still in range. If it isn’t, you get a message such as “Enter between 3 and 18 rungs.”
More rungs make the paths zigzag more, which makes them more fun to follow. They do not change anyone’s odds of getting any outcome.
How the result is decided
The result is fixed the moment you click “Create ladder” or a shuffle button. The cover lifting and the paths being drawn only show a result that has already been decided.
Rungs are placed by these rules.
- First, every gap between two vertical lines gets one rung. If a gap had none, the participants to its left could never reach the outcomes to its right.
- The rest are placed at random among all the positions still available.
- Two neighboring gaps never get a rung at the same height. If one vertical line had rungs on both sides at the same height, there would be no telling which way to cross.
On top of that, the order of the outcomes at the bottom is shuffled at random every time a ladder is built. This step is what makes every pairing of participants and outcomes equally likely, however many rungs there are. With 4 participants and 2 outcomes, 2 of the 4 spots are blank, so each person’s chance of drawing a blank is 2 in 4, which is 50%.
The random numbers for the rung positions and the shuffle orders come from the browser’s crypto.getRandomValues. The rungs are not drawn on screen at all until you click “Show results”, so there is no way to learn the result early by peeking behind the cover.
Picking just a few people with blanks
Because you don’t have to fill in every outcome, the ladder can also pick a few people out of a larger group.
- 1 person out of 6 to buy the coffee: enter a single outcome line, “Buy coffee”. The other five spots are blank.
- 2 people out of 8 to clean up: enter “Clean up” on two lines. The same outcome can appear on more than one line.
- 4 people taking one role each: fill in all 4 outcome lines and everyone gets exactly one, with no blanks.