An Etymological Dictionary of the German Language/Annotated/Schach
Schach, neuter, ‘chess,’ from Middle High German schâch, masculine and neuter, ‘king (at chess), chessboard, checkmating move’; the chessboard was usually termed schâch-zabel in Middle High German, zabel (even in Old High German zabal, ‘chess or draught board’), being changed by permutation from Latin tabula. Middle High German schâch was obtained through a Romance medium from Persian schâh, ‘king’; it is strange, therefore, that the High German word ends in ch in contrast to the Romance cc; compare Italian scacco, French échec. This must be ascribed to a fresh influence of the originally word.