🚣 River crossing puzzles: plan the way back too
In a river puzzle it is not enough to know who needs to cross. You need to think about who stays behind while the boat moves away, and how it will come back for the next passengers.
Check the bank that is left alone
The adult is always in the boat. After each crossing, the bank the boat left has no supervision, so it must not hold a pair from the list of rules. In another level the list of pairs and the boat size may change.
Going back is not always a step back
Sometimes you have to bring a passenger back to make room for the next move. Do not measure progress only by how many are on the far bank; check whether you have reached a state that allows another legal crossing. The adult can also return alone.
Draw the state, not the story
Write two lists: who is on the first bank and who is on the second, and mark where the boat is. If you are back in exactly the same state, you are probably going in circles. The hint in the game looks for a legal route from where you are now.
Questions and answers
Does the adult take up a seat in the boat?
No. The capacity shown in the game is the number of extra passengers. The adult always rows and can cross alone.
Why can I not make the crossing I chose?
You may have picked more passengers than the boat holds, or the crossing leaves a forbidden pair on a bank without the adult. Check the list shown above the river.