Singles

Singles place a digit immediately. They are the first techniques Xodoku tries and the easiest steps to apply by hand.

Full House

A Full House is a row, column, or block with one empty cell. The missing digit must go in that cell.

Hidden Single

A Hidden Single occurs when one digit has only one possible cell in a house, even if that cell has several candidates.

Naked Single

A Naked Single is a cell with exactly one remaining candidate.

Scope

Xodoku treats Full House, Hidden Single, and Naked Single as placement steps. When a hint applies one of these techniques, the next move is to set the shown cell to the shown digit.