Super Confusing Rule 1:
This rule is called 'castling'. Don't worry if you don't understand it right away
because it is a confusing rule!
The rule is this: If there are no pieces between your King and Rook,
and your King is not under attack, and neither your King or your Rook has
moved yet, then you can move them both at the same time!
You can only do this once per game, and you don't get to choose
which squares they move to. The King must move two squares towards
the Rook, and the Rook must move to the square next to the king (on the
Next: Castling on the other side