Quadringentesimus Quadratum

Quadringentesimus Quadratum is a 2002 game by Martin Schlegel, published at Spielbox magazine #4.

Each player has 17 pieces, and there's an extra neutral stone that starts at the central marked square.

Rules

• Players alternately drop their pieces on empty squares, following these rules:
• The first player drops one piece.
• The second player then drop two pieces; the second must be directly east or west of the first.
• The first player then drops two pieces; the second must be directly north or south of the first.
• Play continues in this alternating double-placement pattern, with the required adjacency constraint depending on the previous opponent’s move.
• Pieces cannot be placed on the square occupied by the neutral stone.
• Pieces cannot be placed on a square that lies directly between two opposing pieces in a straight orthogonal line (unless that line is interrupted by the neutral stone or one of your own pieces).
• If a player cannot drop their required second piece, they place only one. 
• Passing is not allowed if a legal placement exists.
• The game ends when all pieces are placed or no further legal placements are possible. 
• For scoring, count all empty spaces that lie between two of your pieces in an uninterrupted orthogonal line. The player with the higher total wins the game.