Rock, Paper, Four!

A twist on four-in-a-row using pieces marked with rock-paper-scissors hands. You win by lining up 4 pieces vertically, horizontally, or diagonally that are either: your color, or the same gesture When you place a piece, all adjacent pieces within 1 space that show a weaker hand are flipped over. At the center of the board is the Guchopa piece. It belongs to neither player and is an invincible piece. Because it is invincible, it does not flip over when pieces are placed around it. It is also treated as all gestures (rock-paper-scissors), so it can be used toward the win condition of lining up 4 pieces with the same gesture.