The one rule that matters most in water sort is this: an empty cup is worth more than any pour you could make into it. Almost every level that goes wrong goes wrong because the last empty cup got filled with a colour that had nowhere else to go.
The rest follows from that. Here is how to play the levels in Water Sort, from the first easy boards to the ones with faucets, locked cups and lids.
The basics in one paragraph
A cup holds four layers. You can pour onto an empty cup or onto the same colour, and matching layers on top move together, so two blue layers on top of a cup pour as one. A level is finished when every colour sits in a cup of its own. Fewer moves earn more stars.
1. Protect the empty cup
Treat an empty cup as a workspace, not a destination. Pour into it only when doing so finishes something or uncovers a colour you can use straight away. If you pour into it just because the move is legal, you have spent the one thing that lets you recover from a bad board.
2. Pour toward the colour closest to done
When two pours are possible, pick the one that adds to the cup with the most layers of one colour already in it. A cup with three reds needs one more. A cup with one red needs three, and you will not get them cheaply.
3. Look at what each pour uncovers
The layer under the one you pour away is the real result of the move. Before each pour, check what is underneath. A pour that reveals a colour you can place immediately is a good pour. A pour that reveals a colour you have nowhere to put has just made the board harder.
4. Don't split matching layers
Pour stacks of the same colour together. If two greens sit on top of a cup and the target has room for only one, the pour moves one green and leaves the other stranded on top of a different colour. Wait until the target has room for the whole stack.
5. Use undo to think, not to cheat
Only the final move count matters for stars, so undo is free in every way that counts. Use it to test an idea several moves deep: try a line, see where it leads, step back if it closes the board. The game keeps up to 120 pours of history.
6. Learn each new mechanic once
Water Sort adds a twist every so often, and each one changes the habits above.
| From level | Mechanic | What changes |
|---|---|---|
| 16 | Faucets | A faucet drains a cup from the bottom into the cup below it, so the bottom layer of the top cup matters as much as its top |
| 91 | Single-colour cups | A marked cup accepts only its colour. Fill it early: it is a free finished cup |
| 181 | Upside-down cups | Some cups flip after a set number of moves, so the bottom becomes the top. Count the moves before the flip and plan for it |
| 301 | Lids | A lidded cup only counts as finished when it is full of the lid's colour, which makes that cup a commitment |
7. When a level looks impossible
It almost never is. Restart, and on the first pass, before pouring anything, find the colour whose layers are closest to the tops of their cups. Start there. Levels that feel stuck usually came from an early pour that buried the colour you needed.
Three stars, or just finished?
Finishing is the first goal and stars are the second. Once a level is done, replay it with the line you now know works and cut the moves that were only exploration. That is also how scores climb on the Water Sort leaderboard.
More puzzles like this are in all puzzle games.