The puzzle setter provides a partially completed grid, which for a well-posed baffle has a single solution.
These Welcome Offers most commonly include absolute match up bonuses up to a certain amount. Developer ResponseHi, Suthrngyrl, be grateful you so much for your advice. It was bad enough that I spent money on coins and after that spent more money on additional coins, for them not to honor my original purchase. Since this applies en route for Latin squares in general, most variants of Sudoku have the same ceiling.