I was playing a game with a friend online. A situation came up where he put me in check with his bishop, and I moved my rook to block it. His king was on the g file and my rook was on g2. The website said he was in check.
[fen "6k1/8/2b5/8/8/8/6R1/7K b - - 0 1"]
Rg2+ , showing only the pieces important to the question.
I didn't think it could be a check, since legally, I could not attack his king or move my rook because it would put my king in check. Can a piece put a king in check even though moving that piece would be an illegal move?
This is odd, because since he was forced to respond to the check, I was able to make a couple moves and leave him with only a couple of blocked pawns, while I was able to promote a pawn and mate in a couple moves. I won, but it feels like cheating. He had a better position and should have won.