In each N-by-N grid, normal N-by-N Sudoku rules apply. Overlapping cells contain the same digit eg if r6c8 is a 4 in the 9x9 grid then it is also a 4 in r1c1 of the 6x6 grid. COUNTING CARDS: A digit in a cell with a suit symbol indicates how many times that digit appears in cells with that suit symbol. Eg if r6c5 of the 9x9 grid contains a 6 then exactly 6 diamond cells in the grid must contain a 6.