Pencil and paper games

These are the Lisp programs used to implement the game playing features of my website Pencil and Paper Games. You can run them in the Listener in any Common Lisp implementation.

Table of contents

• Go-Moku
• Obstruction
• 3D Noughts and Crosses

Go-Moku

The game is played on a large piece of squared paper, at least 15 x 15. The players take turns in marking a square with their symbol (eg O and X). The first player to get five squares in a row, horizontally, vertically, or diagonally, wins.

The interface

O to  move: i7

   A B C D E F G H I J K L M N O (-13) (13)
 1 . . . . . . . . . . . . . . . 
 2 . . . . . . . . . . . . . . . 
 3 . . . . . . . . . . . . . . . 
 4 . . . . . . . . . . . . . . . 
 5 . . . . . . . . . . . . . . . 
 6 . . . . . . . . X . O . . . . 
 7 . . . . . . O O O X . . . . . 
 8 . . . . . . O O X . . . . . . 
 9 . . . . . . . X X . . . . . . 
10 . . . . . . X . . . . . . . . 
11 . . . . . O . . . . . . . . . 
12 . . . . . . . . . . . . . . . 
13 . . . . . . . . . . . . . . . 
14 . . . . . . . . . . . . . . . 
15 . . . . . . . . . . . . . . . 

Running the program

Load the file gomoku.lisp. Then evaluate the following commands in the Listener:

(in-package :gomoku)
(gomoku #'human (alpha-beta-searcher 3 #'count-difference))

You are 'O' and you start. You should give your move as a grid reference such as H7.

If you want to make it easy to beat the computer try:

(gomoku #'human (alpha-beta-searcher 3 #'random-strategy))

Obstruction

The game is played on a grid; 6 x 6 is a good size. One player is 'O' and the other is 'X'.

Players take turns in writing their symbol in a cell. The restriction is that you can only play in a cell if all its neighbours are empty; the available cells are shown as dots on the printed board.

The first player unable to move loses.

The interface

O to move: c1

  A B C D E F (0) (0)
1 O   O       
2           X 
3 .           
4 .   O   O   
5             
6 X   . .   X 

Running the program

Load the file obstruction.lisp. Then evaluate the following commands in the Listener:

(in-package :obstruction)
(obstruction #'human (alpha-beta-searcher 3 #'static-evaluation))

You are 'O' and you start. You should give your move as a grid reference such as D3.

If you want to make it easy to beat the computer try:

(obstruction #'human (alpha-beta-searcher 3 #'random-strategy))

3D Noughts and Crosses

The game is played on a 4 x 4 x 4 board, represented by four 4 x 4 grids in a row.

The players take turns in drawing their symbol, O or X, in one of the cells. The first player to make a line of four cells in any direction wins. Winning lines can be horizontal, vertical, diagonal within one grid, vertical between grids, diagonal between grids, or diagonal in all three dimensions.

The interface

O to  move: e3
  A B C D    E F G H    I J K L    M N O P (-9140) (-8860)
1 . . . X    . . . .    . . . .    . . . .    
2 . . . O    . . . .    . . . .    . . . .    
3 O O . X    O O . O    . O O X    . X . X    
4 . . . X    . . . .    . . . .    . . . X  

Running the program

Load the file 3dox.lisp. Then evaluate the following commands in the Listener:

(in-package :3dox)
(3dox #'human (alpha-beta-searcher 3 #'count-difference))

You are 'O' and you start. You should give your move as a grid reference such as J3.

If you want to make it easy to beat the computer try:

(3dox #'human (alpha-beta-searcher 3 #'random-strategy))