[ysmqgzjh] Chess ponds and columns

Consider a chess variant in which certain squares are designated not accessible: no piece may occupy them.  There are two possibilities: if a ranged piece (e.g., rook, bishop, queen) can fly over that square, then it is like a pond.  If the ranged piece is blocked, then it is like a rock column.

Pawns easily get blocked by these squares (of either type).

There is one more related possibility: a square may be occupied but a ranged piece may not fly through it; it must stop on the square.  This like a rough patch or a sticky spot.

Squares could be randomly set at the beginning of the game providing initial variation like Chess960, or they could change state during the game, perhaps something some pieces can do.