TappyPotato logic puzzles

Classic logic puzzles

River crossing — rules and where to play

RIVER CROSSING · Wolf-goat-cabbage / Missionaries and cannibals

People and goods cross in batches; the boat holds few; some pairs cannot be left alone. At heart a state-space search.

Origin
—
Difficulty
★★★★★ 2–4 / 5
Time
10–30 min
Grid
—
Sites
2

Rules

  1. All actors move from one bank to the other; the boat carries a limited load (often with a rower).
  2. Some actors cannot be left together unsupervised (e.g. wolf eats goat).
  3. A transfer sequence that never breaks a rule is the solution.

How to start

Enumerate states, not steps

Track "who is on each bank" as a state to avoid revisiting.

Handle the riskiest constraint first

Keep the incompatible pair separated or supervised at all times.

Prune by parity

Parity of certain counts can rule out dead ends directly.

Where players get stuck

  • Tracking steps but not states, looping back thinking you advanced.
  • Forgetting the rower must also cross, leaving no one to row.

Play River crossing

2 sites
BrainBashersFree

Been free for years. A daily logic set, plus Sudoku variants, Kakuro and Nonograms.

Open → Erich's Puzzle PalaceFree

Erich Friedman's long collection — 130-plus types, all over the map.

Open →

Browse All-in-one portals →

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About this page
  • Last updated 2026-09-22
  • Source Curated compilation of established puzzle rules and listed third-party play sites
  • Audience Players learning River crossing rules or looking for online sites to play
  • Covers Rules summary, how to start, common pitfalls, and the dedicated play sites listed on this page
  • Does not cover Hosted puzzles, worked solutions, official contest rankings, third-party uptime or pricing guarantees
  • Not advice This page is puzzle reference content only. It does not constitute financial, legal, medical or other professional advice.
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