Vudoku (PuzzleMadness)

About Vudoku (PuzzleMadness)

The usual sudoku rules apply: 1 to 9 once in every row, column and 3x3 box. The V clues are little right-angle marks drawn at a cell corner, each one pointing into three cells that form an L. Among those three digits, any two must add up to the third, as in 2, 5 and 7 or 3, 6 and 9. The clue does not say which cell holds the total. Where two V clues overlap, each is checked on its own.

The largest digit in a V is always the sum, so it cannot be 1 or 2, and a 9 in a V forces the other two to be one of the pairs 1 and 8, 2 and 7, 3 and 6 or 4 and 5. Small digits appear often: a 1 in a V means the other two are consecutive. Today's Medium grid, for example, has V clues scattered across most of its boxes.

The grid works like every sudoku on PuzzleMadness: number buttons above and below it, an eraser, and a pencil mode for candidate digits. On a keyboard, the number keys enter digits, the arrow keys move between cells, Ctrl, Shift or Alt with a number adds a pencil mark, and Delete or Backspace clears a cell.

PuzzleMadness is a free puzzle website run by Dewi, a software developer who started out making games for the PlayStation 2, Nintendo Wii and DS and now builds the site as a hobby. It carries dozens of puzzle types, from classic sudoku to newer logic grids, and each one gets its own dated puzzle every day at each difficulty. Vudoku comes in Easy, Medium, Hard and Tough versions plus a Mixed page, and the same day's Vudoku puzzle is shared by everyone who opens it.

The site checks your grid as you go and tells you when it is finished; it does not publish solutions. Each completed puzzle earns a score, and scores feed a monthly and an all-time Vudoku leaderboard, where only your best attempt at a puzzle counts. Older days stay in the archive, so a missed puzzle can still be played later and still counts toward the current month. Playing needs no account; a free registration gives you a username on the leaderboards and a cloud save. The pages carry adverts.

How to play Vudoku (PuzzleMadness)

1. Open today's Vudoku page on PuzzleMadness and choose a difficulty from the menu above the grid.
2. Click a cell and enter a digit with the number buttons above and below the grid or with the keyboard; the eraser button clears a cell.
3. Fill every row, column and 3x3 box with the digits 1 to 9, each once.
4. For each V clue, make two of its three cells add up to the third.
5. Turn on pencil mode (the pencil button, or Ctrl, Shift or Alt with a number key) to jot candidate digits in a cell.
6. The site tells you when the grid is complete and adds your score; registered players appear on the leaderboards.

Screenshots

Tips

• The biggest of a V's three digits is the total, so 1 and 2 can never be the largest; 1 can never be the total at all.
• A V with a 1 in it holds two consecutive digits in its other cells.
• Two V clues sharing a cell give two sums through one digit, which often pins it down.
• Missed a day? Earlier puzzles are in the archive, and finishing one still counts toward this month's leaderboard.

Questions