Sudoku1 can play Sudoku classic, but also variants derived from world championship 2007, 2008 and 2009.

This is available at the launch of the generation of grid, together with selection of the size of the board (4x4 to 16x16 through classic 9x9), of display and of difficulty.

The following variants are available:

- Irregular: instead of the classic block of 3x3 in a grid of 9x9 squares, a block can be defined with different figures including any area of 9 cases.
- Diagonal: in the 2 diagonals, all figures should be different, in addition to the rows, columns and blocks.
- Distance: information are shown for the rows and columns given the number of cells identified between 2 figures
- Little-Killer: cells of diagonals have defined their sum indicated by the arrows
- Killer: cells framed in the dotted have their sum defined
- Even and Odd: the value of the cell is Odd or Even.
- Higher or Lower: The value of a cell is over or under the other cell
- Dot: The difference (Dot full) between 2 box is 1 or-1, or a cell (Dot blank) is twice the other.
- Battleboats: boats are listed on the side, together with the number of cells with boats in rows and columns. You should find boats
- Puzzle: pieces of the puzzle are shown on the side, that you have to put in the grid.
- XV: the sum of 2 cases is equal to 5 or 10.
- Trio: Every cell with a symbol (circle, square losange or trangle) must include a value indicated in image bar.
- Numeral: The word corresponding to the call number contains the background letter.
- Outside: Number oustide the grid must be included in lines or columns of the contiguous block.
- Oddview: Numbers outside grid indicate the first Odd and Even number in the line or column.
- Frame Sum: Numbers outside gris give the sum of the 3 cells in contiguous line or column.
- Frame Prod: Numbers outside gris give the product of the 3 cells in contiguous line or column.
- Tiled: Pieces of puzzle must be set in grid. pieces can be turned or mirror, but with point to be set in grid edge.
- Quad Max/Min: The Black (white) Point in the circle indicates the bigger (lower) number in the group of 4 cells.
- Extra Region: The 2 colored area contains also all number between 1 to 9.
- Pencil: Is some cells, you find all possible allowed.
- Domino/Pips: The domino indicated the value in the cell. But some domino pipes are indicate and other are masked.
- Digital clock: The number written with segment indicates the cell value. But be aware that some segment have been forgot.
- Romain: Value in the cell are indicated in Romain Les chiffres romains indiquent la valeur de la case. But be aware that some are partially written.
- Magic sentence: Every row, column and block contain given letters. If your sudoku is solved you can find in the cells with a magic pen a sentence or word..
- Kimo: The numbers in tell you the modulo of the sums of the framed cells..
- non-consecutive:  Every cell contains a number which is not consecutive with neighbouring cells in line or column.
- Arrow Sudoku:  The digit in a circle is the sum of the digits which are marked with its arrow.
- Creasing Sum line:  Numbers going along the connected cells lines must be in increasing or decreasing (>);
in consecutive order (=); alternativly increasing/decreasing (<>); or one number is the sum of the others (+)
- Dan: All cells with small Dn on the left bottom part must use no more than indicated value N.
- Equality:  The digits in the cells with same colored = on left bottom part must be equal.
- SkyScraper: Some numbers in rows or columns are transferred in the frame one after the other, with cells with cross not taken into account.
- Wheel: The wheels in the grid contain each 4 values. These values will go in the cells the numbers are in.
- Pan digital:  Rows or colomns form correct arithmetic expressions, with compared value given by all digits of the block.
- Navigator:  The arrows show the location of the same number in the previous or next column, row or diagonal.
- Last Number:  A blue arrow (going up) means that the digits are going up till they hit this number, and for a red arrow (going down) they go down till they hit this particular number.
- Chess sudoku: Each Chess figure replace one digit. All Black figures must defend themselves, as white figures must not attack themselves.
- Magic Square:  The area with star marks includes a magic square, i. e., the sums of any row, any column and both main diagonals in this area are always the same.
- Transfer sudoku:  Some numbers in rows or columns are transferred in the frame one after the other, with cells with cross not taken into account.
- Twins Relation:  In this variant, you have to solve 2 grids simultaneously, 2 grids with common cells hatched (with the same value).
- Twins Substitution:  This variante has 2 grids with cells being in relation from one to the other.
- Twins Zone:  In the 2 grids, blocks of same color have identical cells.
- Twins Equal:  The 2 grids have the same solution
- Twins Different:  All values of the 2 grids are different cell by cell.

At the grid generation, you can combine one or more variants. Sudoku1 selects randomly combination where you will have a lesser number of boxes filled.

To solve the grid when variant, you can have a look here.

For the experts, you can enter or create an alternative in Debug mode, using the following keys.