About Flood It
Flood It is played on a 14 x 14 board of coloured squares. The flood starts in the top-left corner, and each time you pick a colour, the whole flooded area changes to that colour and swallows any touching squares of the same colour. You need to cover the entire board in 25 moves or fewer.
How to play
- The board is 14 x 14 squares in six colours, chosen at random.
- Your flood is the group of squares connected to the top-left corner by the same colour, through edges, not diagonals.
- Choosing a colour repaints the whole flood in that colour, so it joins up with every neighbouring square of that colour.
- Choosing the colour the flood already has does nothing and does not use a move.
- You win if the whole board is one colour within 25 moves, and lose if you use all 25 without filling it.
- A win scores 26 minus the number of moves you used, so finishing in 20 moves scores 6 and finishing on the 25th move scores 1.
Controls
- Mouse or touch: click or tap one of the six colour buttons below the board.
- The button for the flood's current colour is ringed.
- There is no keyboard control for this game.
Tips and strategy
- Grow toward the far corner first. Pushing a long arm across the diagonal of the board opens up the most new edges for later moves.
- Each move, think about which colour touches the most of your flood's border, not just which colour has the biggest patch nearby.
- Watch for colours that are about to disappear. If the only remaining squares of a colour all touch your flood, picking it removes that colour from the board entirely.
- Near the end, count the colours still showing outside the flood. If four colours remain and you have three moves left, you will not finish.
- Keep an eye on the Flooded percentage. Around halfway through your moves you usually want well over half the board.
Background
Flood It belongs to a family of flood-filling puzzles that have appeared as web, desktop and mobile games, and a version called Flood is included in Simon Tatham's Portable Puzzle Collection. The puzzle has attracted mathematical interest: researchers including Raphael Clifford and colleagues showed in 2012 that finding the fewest moves needed to flood a board is NP-hard when there are three or more colours.
Questions
- Can every board be finished in 25 moves?
- Not necessarily. Boards are random and the game does not check that a 25-move solution exists, though most boards can be done with careful play.
- Where is my best score kept?
- In your browser's local storage on this device. Only wins score, and fewer moves means a higher score.