Normal sudoku rules apply. Fog may be cleared by correctly placed digits. Digits a knight's move away can not be identical. Digits in a cage cannot repeat. If a number is given in the upper left corner of the cage, then the digits in the cage must sum to that number. Each cage is either full of "oil" (even digits), full of "water" (odd digits), or a mix of both. In cases where cells of a cage are connected to each other horizontally, those cells must only contain one type (oil or water). If two cells are a part of the same cage and in the same row, but they are not connected horizontally (r5c6 & r5c8 for example), then they can be different types. Oil floats on water, so even digits will always be in rows above odd digits in mixed cages.
If you prefer to play directly in sudokupad then click below.
