Simple Multiplayer Chess Game...

ChessGame.java

public class AbstractPosition {}

protected class ChessPiece {
		enum color
		enum player
		// not really needed
		is_alive
		protected boolean is_valid_move(int x1, int y1, int x2, int y2);

}
public class AbstractGameManager {
		piece player1_pieces[];
		piece player1_pieces[];

		GameManager() {	
		}
                public getCurrentSituation() {
                }
                public isMatchConcluded() {
                }
                public whoWon() {
                }
		public boolean move(player, positioin1, position2) {
		
		}


}

/* Just have child classes with different implementations of is_valid_move */

protected class Horse extends ChessPiece {
		protected boolean is_valid_move(int x1, int y1, int x2, int y2) {
			// Some implementation
		}

}

protected ChessBlock {
	color
	piece
	has_piece()
	get_piece()
	set_piece()
}
.....
.....
....
public class ChessBoardManager {
		public static final BLACK = True;
		public static final WHITE  = False;
		public static ROW_LENGTH = 8;
		ChessBlock chess_blocks[][];
		piece player1_pieces[];
		piece player1_pieces[];

		ChessBoardManager() {
			chess_blocks = new ChessBlock[ROW_LENGTH][ROW_LENGTH];
			int row_counter = 0;
			
			for(int row_counter=0; row_counter < ;) {
				
			}
		}
		
		move(player, x1, x2, x3, x4) {
		
		
		}


}