Calling out to DreadedHermie for a game of "stoner chess"

[Weezard]

I could see opposite color from opposing bishop.

What makes this useful with a rook?

Rooks are linear but very mobil.
A knight is non linear but less mobil.
A knight attacks indirectly. And, in the center of the board they threaten 8 squares.
If on a black square, they threaten 8 white squares and vice versa
That allows it to attack a rook without danger of getting, well, rooked.
Thus a knight can threaten the rook and attack the king at the same time if they are both on the same color.
One MUST move the king.
Goodbye rook, or queen.
It's called a knight fork
So, yer either gonna get rooked, or forked, yah?

W.