The Korean 사다리타기 / Japanese あみだくじ ladder draw. Enter N participants and N outcomes; randomly placed horizontal rungs connect each name to exactly one outcome. Click a name to trace its path.
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Type one participant per line on the left and one outcome per line on the right. The number of outcomes should match the number of participants — extra outcomes are dropped, missing ones are padded with em-dash placeholders. Click any participant label to trace their path from top to bottom; click again to hide. **Reveal all** shows every participant's route at once, color-coded.
Mechanically the ladder is a bijection — a permutation from the top row to the bottom — so each outcome is taken by exactly one participant. Horizontal rungs are placed with ~45% probability per cell, with the constraint that two rungs cannot share a row at adjacent columns (otherwise the trace would be ambiguous). **Regenerate** redraws the rungs while keeping the same participants and outcomes.
participants: Alice, Bob, Charlie, Dave outcomes: Alice, Bob, Charlie, Dave (same names, will be permuted)
Alice → Charlie Bob → Dave Charlie → Bob Dave → Alice
A classic use of 사다리타기 / あみだくじ — pair each person with a gift target. Note the bijection means it may produce a self-mapping (Alice draws Alice) for some random seeds; the workaround is to regenerate until no self-mapping appears, which is fine for small N.
participants: Alice, Bob, Charlie, Dave outcomes: dishes, vacuum, trash, laundry
Alice → laundry Bob → dishes Charlie → trash Dave → vacuum
The bijection guarantees every chore is assigned exactly once and no one gets two. Perfect for shared apartments or weekly rotations — regenerate the ladder each week to shuffle.
Close but not exactly. Each cell independently gets a rung with ~45% probability (with the adjacency constraint). The induced permutation is biased — adjacent swaps are more likely than long-distance moves — but for casual party use the bias is invisible and every permutation has nonzero probability. If you need a strictly uniform permutation, use a Fisher-Yates shuffle on the outcomes list instead.
If two rungs share a row at columns `c` and `c+1`, a person walking down on column `c+1` arrives at the rung and has to choose: take the left rung (back to `c`) or the right rung (forward to `c+2`)? The traditional rule resolves this by processing rungs left-to-right, but visually it looks like the trace teleports past a rung, which confuses observers. Forbidding the case keeps the trace honest: at any row, at most one rung touches each column.
The tool will pad outcomes with em-dash placeholders if you have fewer than participants, or truncate the extras. But the ladder structure requires N == N — a participant cannot be mapped to "nothing." If you genuinely have unequal counts (more participants than prizes, say), use the roulette tool with the elimination mode instead, or pad your outcome list with explicit losers ("pass", "꽝", "ハズレ").
The Japanese form, あみだくじ (`amidakuji`), is named for the buddha Amitābha (阿弥陀, `Amida` in Japanese) — historically the lines were drawn radiating from a center like a halo around the Amida buddha. By the Edo period (17th–19th c.) the radial form had become the modern parallel-lines-with-rungs layout, used for shared payment ("who pays the round?") and chore assignment. The Korean 사다리타기 (literally "ladder climbing") arrived later via Japanese influence and remained a fixture of school field trips, drinking games, and TV variety shows. The tool encodes the universal rule: equal slices for everyone, no peeking, the ladder decides.
Spin a roulette wheel of names or items to pick one at random. Each entry gets an equal slice; the wheel decelerates with realistic easing and shows the winner. Optional auto-remove for tournament-style elimination.
Shuffle a list of names into balanced teams. Choose either the number of teams or the size per team; teams come out within 1 member of each other. Optional team names and one-click copy.
Shuffle a list of names into a fixed sequence — 1st, 2nd, 3rd, … Choose between instant reveal, sequential auto reveal with adjustable speed, or click-to-reveal where you pace the announcement yourself. Good for presentation order, karaoke turns, interview slots, or anything that needs a fair line-up.
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