Anti checkmate mechanic

How can I disable the anti checkmate thing where in a check you can't move anything which doesn't protect the king? It's really annoying. 

Maybe this will help?

When you are in check you must escape check. The ways to get out of check are to move the king, block the check with another piece or to capture the checking piece.

I know but I don't want to be forced to do it, because for example i might not know that I'm in a check, and the opponent can win the game easily, but he can't because I cant move anything and only then I notice that I'm in a check, ruining the opponent's plans. 

But those are the rules of chess...Maybe I'm missing something here.  Any one else have an idea?

He just doesn't understand the rules

That would be a variant of chess, not chess. It's illegal to do anything else and the site does not allow illegal moves and it doesn't make sense to allow them.