How to Play Water Sort: seven rules for getting unstuck
Water sort looks like it rewards speed and actually punishes it. Every board here is built backwards from a finished state, so it can always be cleared, and an independent solver computes the shortest solution — which means getting stuck is always about the order you poured in, and always undoable.
-
Only pour if the pour frees something
A legal move is not a good move. Before pouring, ask what it uncovers: a new colour, an emptier tube, a completed stack. If the answer is nothing, you have just made the board harder to read.
-
Keep one tube completely empty
An empty tube is the only place an awkward colour can go without landing on top of something. Losing your last empty tube is the single most common way a winnable board becomes a puzzle you cannot untangle.
-
Count what is left of each colour
There are exactly four units of every colour. If you can see all four, you can plan the whole gather. If you can only see two, the others are buried and that colour is not yet the one to work on.
-
Never bury a colour under a different one
Pouring onto a stack you will need to dismantle later trades a small problem for a bigger one. The exception is the final pour that completes a tube — there is nothing left to dig out.
-
Consolidate before you open anything new
If the same colour sits at the top of two tubes, join them first. It costs one move and buys back the space that all the other tips depend on.
-
Use undo as a test, not a rescue
Undo costs nothing here. Try the line you are unsure about, look at the position it produces, and step back. That is much faster than reasoning about it in your head, and it is why the optimal count is worth chasing.
-
Every board can be cleared, so a dead end is a move order
These boards are generated in reverse from a solved state, so a solution exists by construction. When you jam, do not restart — undo to the point where you poured onto something you later needed.
The empty tube is the whole game. Almost every unsolvable-looking position turns out to be the moment the last empty tube was spent on a pour that freed nothing.