Your first clue....This is what it looks like....

It has No Queen, but a King (Moves like
today's Queen), a Prince (moves like today's King),
FOUR Bishops (Same move as today's), FOUR knights
(Same move as today's), 2 rooks (Same move as today's)
and 12 pawns (Same move as today's)!

The King is to be "in harmony" with his land.
Gold King on gold square, Silver King on silver square.

Then, Wage War.

(The king position on the chessboard, at game
setup, must match it's piece color.)

The Prince must accompany his father, The King,
to the battlefield. There, The Prince is instructed in
The Science of Warfare (THE ART OF WAR).

If the King is still alive, his son, the prince CANNOT
move on the battlefield, like his father.

(This is a sign of respect for his father, The King).

The Prince moves one step at a time, on the battlefield.

(This must mean, the prince moves only one square at a
time, in any direction - just like the king moves, in
the old chess system.)

The King is to pick 4 of his wisest advisers and 4
of his bravest knights to go to war.

(This must mean, there are 4 bishops and 4 knights instead
of 2 ! From what I understand, the knight & bishop move on the
chessboard, in the same way as they did in the old chess system.)

The Pawns also move as they did in the old chess system, but
when a Pawn reaches the end of the battle field, it can be
promoted to : (a) A Rook (ii) A Knight (iii) A Wise Man (A Bishop).

THE PAWN IS NOT TO BE PROMOTED TO A KING OR A PRINCE
(Because that is to Usurp POWER).

As of yet, there is NO MENTION of Castling
or the "en passant" rule anywhere.

If the King is slain, The Prince automatically becomes The New King.

If The new king (should the game have one) is checkmated:

Their Kingdom falls.

The Game of War Ends.