submodules/rlp/puzzles/html/solo.html

Solo
<p>
Fill in a number in every square so that every number appears
exactly once in each row, each column and each block marked by thick
lines.
<p>
To place a number, click in a square to select it, then type the
number on the keyboard. To erase a number, click to select a square
and then press Backspace.
<p>
Right-click in a square and then type a number to add or remove the
number as a pencil mark, indicating numbers that you think
<em>might</em> go in that square.
<p>
When you master the basic game, try Jigsaw mode (irregularly shaped
blocks), X mode (the two main diagonals of the grid must also
contain every number once), Killer mode (instead of single-cell
clues you are given regions of the grid each of which must add up to
a given total, again without reusing any digits), or all of those at
once!