The Welcome Screen is the first thing you see when you start KSudoku or use the toolbar or menu to request a new game. It has a list of all the puzzle types and sizes and you can click on one of them to make a selection.
If you click the button marked Enter In A Puzzle, an empty board of the selected type and size appears. Here you can use the mouse or keyboard to enter in a puzzle from another source, such as a newspaper. When you have finished, use the Check action, on toolbar or menu, to check the puzzle. It should have just one solution. If so, you can start solving the puzzle or perhaps get KSudoku to solve it. If there is no solution or more than one solution, it probably means you have made a data-entry error somewhere.
If you click the button marked Generate A Puzzle, KSudoku will display a board with some squares already filled in. It is up to you to fill in the rest.
Before you generate a puzzle, check that the settings of the Difficulty and Symmetry buttons are to your liking. You can change them during a game, but then they will have no effect until the next puzzle is generated.
If you cannot see the Difficulty and Symmetry buttons, use the → menu item to make sure that the statusbar is visible.
The Difficulty button provides six levels of difficulty, from up to , and . The easier levels may take a few minutes to solve on a 9x9 board. The and levels may take an hour or so and are intended to be equivalent to difficult grades appearing in newspapers. Samurai puzzles and 16x16 or 25x25 sizes of puzzles will take longer to solve, simply because there are more rows, columns and blocks and more squares to fill in.
The Diabolical level typically requires one or more guesses, with backtracking if you guess wrong. Lower levels can usually be solved by logic alone. The Unlimited level has no limits on the number of guesses required, how soon the first guess is needed or how complex the logic might be. It is provided for the interest of expert players, but tends to generate uninteresting 'inhuman' puzzles and is not recommended for general use.
The Symmetry button provides seven types of symmetry, including . This controls the layout and appearance of the squares that are filled in at the start of a puzzle and has mainly aesthetic effect, except that puzzles with no symmetry tend to be slightly harder than those with high symmetry and it is less likely that KSudoku can generate a puzzle with high difficulty and high symmetry combined.