The queen and the king
The queen
Any straight line or diagonal, as far as it likes: the strongest piece.
The king
One square in any direction. It is the piece you must never lose.
In the middle of the board the king has 8 squares, on an edge 5, in a corner 3. The two kings can never stand next to each other.
The king is never captured. When it is attacked and cannot escape, the game is over: that is checkmate, which comes in Unit 2.