In 1987 the University of Central Florida's chapter of Association for Computing Machinery (ACM) held a programming contest in which contestants had to develop a program that allowed a person to play a game against the computer. The rules of the game were defined and the contestants were given about six weeks to implement a solution. Below are the rules for the game and a link to run the winning game developed by John Weidner.
 
Name: Lattices
Equipment: A standard eight by eight checkers board. 67 playing chips labeled with the numbers 1 through 64 plus three extra chips labeled with the number 1. Each chip has the number painted red on one side and blue on the other. Four additional white chips.
Setup:Place the four 1 chips on the board as indicated by the diagram below and place a white chip on top of each of the ones.
 
8 x 8 grid
Objective:When the board becomes full of chips, have more chips on the board with your color displayed then your opponent has. If both players have 32 pieces, the one with the highest sum of all their pieces wins.
Rules: Players take turns selecting one of the unused numbered tiles and placing it on the game board in any of the unoccupied squares. After placing a tile on the board, the entire board is examined to see what tiles are related using the following definition. Two numbers are related if one number is evenly divisible by the other. (For example 15 would be related to 1, 3, 5, 30, 45, and 60. 20 would be related to 1, 2, 4, 5, 10, 40 and 60). For each piece on the board, you count the number of your pieces that are both adjacent (horizontally, vertically, or diagonally) and related to the piece. At the same time, you count the number of your opponent's pieces that are both adjacent and related to the piece. If for any of your opponent's pieces, the number of your adjacent and related pieces, out numbers the number of your opponent's adjacent and related pieces, then you "capture" the number and flip it so that the piece is now displayed with your color face up. The four 1 pieces with the white chip on top, are considered initially neutral. As soon as either player places one of their pieces adjacent to the one, the white chip is removed and the 1 is flipped so that it is displayed in that player's color. After any piece is captured, you must re-examine all the adjacent pieces, and determine if multiple pieces get captured on the same turn.
John Weidner's DOS implementation of this game beat all the other entries. Download lattices.exe If your computer doesn't run DOS, you might want to use the DOSBox for Google Chrome.
 
After downloading and opening the lattices.exe file, you will be prompted to specify whether each player is a human or the computer by pressing an H or a C. When it is a human's turn, a cursor will be displayed on the game board that you move around using the arrow keys on your keyboard. After positioning the cursor, in the square where you'd like to play a piece, type in the number that you'd like to play in that square. The game will then automatically determine which if any pieces get captured.
 
The following keys may also be used:
   F5 - if you position the cursor on an already occupied square, you may press the F5 key to see which of the unused tiles are related to that piece.
   F9 - pressing F9 will allow the computer to take over the game and automatically play out the rest of the game.