Game guide · 2COPE
Water Jug Puzzle: from controls to your first round
Check the rule below as you play. Measure the target number of litres using two unmarked jugs and only filling, emptying and pouring. Choose one of six capacity-and-target puzzles. Both jugs begin empty.
Six verified solvable capacity puzzles, with undo and move count. These are six levels of one game, not six separate games.
A small practice goal
Keep the goal in view while choosing a move. A pour stops when the source is empty or the destination is full. It cannot stop at an arbitrary amount. Start a new round when you are ready to try again.
What the game asks you to do
Check the rule below as you play. Measure the target number of litres using two unmarked jugs and only filling, emptying and pouring. Start a new round when you are ready to try again.
A walkthrough of the rules
- Choose one of six capacity-and-target puzzles. Both jugs begin empty.
- Fill a jug to its capacity, empty it completely, or pour from one jug into the other.
- A pour stops when the source is empty or the destination is full. It cannot stop at an arbitrary amount.
- Reach the target quantity in either jug. Undo lets you try another route.
Getting comfortable with the controls
Begin with the basic rule, then follow the result of your action. Use Fill A, Fill B, Empty A, Empty B, Pour A → B and Pour B → A. The display shows current and maximum litres. Try the rule on the board, then read the next instruction.
Learn from a sample situation
Begin with the basic rule, then follow the result of your action. With 3- and 5-litre jugs, fill the 5-litre jug and pour into the 3-litre jug. The 5-litre jug now contains 2 litres. Keep the goal in mind before your next move.
Avoid this misunderstanding
The example and rules describe the same game you can play above. You cannot measure a partial fill directly. Only the allowed actions can create a quantity. Keep the goal in mind before your next move.
A few questions answered
What is the aim of Water Jug Puzzle?
Measure the target number of litres using two unmarked jugs and only filling, emptying and pouring. The instructions above use these same rules.
During a round, how do the controls work?
Use Fill A, Fill B, Empty A, Empty B, Pour A → B and Pour B → A. The display shows current and maximum litres. Keep the current game state in view while applying this rule.
For this game, can you show an example?
With 3- and 5-litre jugs, fill the 5-litre jug and pour into the 3-litre jug. The 5-litre jug now contains 2 litres. The worked example offers another way to follow the rule.
For this game, which mistake should I avoid?
You cannot measure a partial fill directly. Only the allowed actions can create a quantity. Scores here do not represent cash or prizes.
On this page, what rules and limits are used here?
Six verified solvable capacity puzzles, with undo and move count. These are six levels of one game, not six separate games. The instructions above use these same rules.
When I start, how many people can play here?
Solo. This is local browser play, not internet matchmaking. The instructions above use these same rules.
Where must the target volume end up?
In either jug. The other jug may contain any legal amount. Use the labelled controls for your next action.
During a round, can I stop a pour halfway?
No. The source must empty or the destination must fill. No download or player account is required.
Why is an action disabled?
It would not change the current jug contents, such as filling a full jug. Keep the current game state in view while applying this rule.
For this game, how many puzzles are included?
Six capacity-and-target combinations are selectable on the board. Scores here do not represent cash or prizes.