Simple really, @Gaming crew…
What do you have to do? Make sure that numbers 1-9 are in every cube of nine, as well as each horizontal and vertical line.
We start with a starter Sudoku puzzle. Then each user copies the puzzle from the previous poster and can add OR remove ONE number. One number per turn and you have to wait for someone else to reply before you can past again, no double-turns in a row.
When the puzzle is solved a new one will go up.