Is this an illegal chess move? Can the White king move to g2 to checkmate?
8/8/8/8/4Q3/7k/5K2/8 w - - 0 1

1. Kg2
Playing Kg2 in this position would &quot;put your king in check&quot; in that the black king is attacking that square already. So, no, that would be an illegal move.
The fastest way to checkmate in this position would be Qd4 (forcing the black king to move to h2) followed by Qh4#.