Logic Masters Deutschland e.V.

RCB Sudoku: RCB Sudoku Rules apply; place the digits 1-6 and the letters R, C, and B, once in every row, column, and 3x3 box. For R, C, or B, their value is equal to their row, column, or box respectively.

Quadruples: Each digit or letter in a circle must appear in the surrounding four cells at least once.

Duality: Each Quadruple also contains an invisible arrow, where one cell must equal the sum of the other three.

Expected Difficulty: 4.5 stars

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