The
Dots & Boxes Game
User Manual
Version 1.0
1
Introduction to Dots & Boxes
1.1 The History of Dots & Boxes
Dots & Boxes is a paper and pencil puzzle game that has
been used to entertain children in cars and occupy mathematicians and
statasticians for many years. (If you
don’t believe me, check out www.math.berkeley.edu/~berlek/cgt/dots.html.) This implementation of the game features a
computer board manager to control the play of two humans.
1.2 The Rules of Dots & Boxes
The game play area of Dots & Boxes consists of an 8 x 8 grid of “dots”. A player’s turn consists of connecting two horizontally or vertically adjacent dots with a line – diagonal lines aren’t allowed and the dots must be next to each other. A point is scored each time a player completes a square. When a square is created, the turn stays with the player who made the square, otherwise the turns alternate.
Notice that the player must complete the square to get points – even if you provide three of the sides, if your opponent fills in the fourth side, he gets the points. It’s customary to fill in the square with the initial of the player who won the square. Since both players usually avoid putting lines close together until they have to, when it becomes possible to make one square, there’s a whole cascade of possible squares. The player who makes the first square in such a cascade can elect to take any or all of the possible squares – there are some strategic schools of thought that say it’s better not to take them all. The game is over when all the dots are connected and 49 squares have been made.
In this implementation, the computer provides dots and the
lines between them. You make line
between two dots by clicking with your mouse on a point on the line connecting
the two dots. Player 1’s lines are
light blue, Player 2’s are dark blue.
When a square is completed, instead of intials, the square is filled
with a color, light blue for Player 1, dark blue for Player 2. The game keeps track of score for you and
prevents illegal moves. Help, which
explains the use of the controls and the play of the game is always available
via the Help button. You can quit the
game, restart the game or get help at any time.
1.3 Game Requirements and Installation
Dots & Boxes requires a computer with a pointing device of some sort and Java 1.2 or higher installed. To get a copy of Java 1.2, visit http://java.sun.com. It will work on Windows 9x and NT and unix operating systems. Memory requirements are TBD.
Install Dots & Boxes by storing the Dots & Boxes.java file and the help.file in the same directory on your personal computer. To run it, type ‘java dotsandboxes’ and, within a second, the game board and controls will be displayed.
2 Using the Game
2.1 Terminology
The terms used in this User Manual and to play the game are shown in Figure 2.1 and explained below.
Figure 2.1 Dots, a Box, Lines and the Cursor
Box - A box is created when four dots that form the corners of square are connected. The game automatically fills in the square. Each square is worth one point for the player who completes it. In the case of Figure 2.1, player 2 (light blue) completed the square.
Cursor - controlled by the mouse and used to select lines and different controls. In Figure 2.1, the cursor is positioned for the player to select the gray line segment with a left mouse click.
Dot - Dots form the grid the game is played on. There are 64 of them making up the 8 dot by 8 dot gameboard matrix. See Figure 1.
Line - the connectors between the dots. In this implementation, the dots are static, the lines detect the player's selection. A line is formed between two dots by clicking on the gray line segment directly between them. After a line segment has been selected, it is colored to indicate the player who selected it, dark blue for player 1, light blue for player 2. Only the gray segments are legal to choose. See Figure 1.
2.2 The User Interface
It’s pretty easy. When the game comes up, you’ll see an empty game board and some buttons, as in Figure 2.2.
Figure 2.2 Dots & Boxes Gameboard after Initialization and Restart
There are only a few controls and all of them are invoked by positioning your cursor over the control, and right clicking on them with your mouse. Here’s what each control does:
a) Restart – Clicking on Restart sets both players' scores to 0 and clears the gameboard of any previous activity. You can always press Restart when the game first comes up (although it's unnecessary at that point), to restart in the middle of the current game, or to start another game after a previous game has been won.
b) 
Help – Clicking on Help will display a text description of the rules of the game and
use of the game controls. Use the close
window icon to get rid of the help window.
c) Quit - To quit, just close the main window. The control is always active, so you can quit at any time.
d) Score – Displays the current score for Player 1 and Player 2. They are initially set to zero and updated as play progresses.
e) Status - The Status area is used for prompting the players to take an action, to display error messages, and to announce wins or ties.
f) Connecting Dots - Use your cursor and mouse to select the line segments between two dots by positioning the cursor over the line segment outlined between two dots. Only the gray segments are legal moves.
3 How To's
3.1 How to Start a New Game
After making sure the game is in the directory you are currently in, open a DOS command window
|
Player Action |
Dots and Boxes |
Req Para. |
|
Type "java
dotsandboxes" |
a)
Game initializes and
displays clear game board (See Figure 2.2). b)
The Quit game
control is visible and available for player input. c)
The Restart control
is visible and available for player input. d)
The Help control is
visible and help information is available for the players to view. e)
The Status area
instructs Player 1 to make a move. f)
A scoring area appears
with scores set to 0 for both players. |
7.1.1.2.a, 7.1.1.3.f 7.1.1.2.b, 7.1.1.3.a 7.1.1.2.c, 7.1.1.3.b 7.1.1.2.d, 7.1.1.3.c 7.1.1.2.e, 7.1.1.3.d 7.1.1.2.f, 7.1.1.3.e |
Table 3.1
Starting Dots & Boxes
3.2 How to Play a Game
First, the clear gameboard must be displayed. After that, play continues as described below. The only legal line selections are the gray ones, and these instructions assume that you'll only pick legal moves. Later, there is paragraph describing what happens when you make an illegal move.
|
Player Action |
Dots & Boxes |
Req. Para. |
|
1. Player 1 positions the cursor on a gray
line segment and clicks the mouse |
a)
The line changes
from gray to dark blue. b)
The "player
turn" message changes to prompt Player 2 to play. |
7.2.1.1 7.3.1.2 |
|
2. Player 2 positions
the cursor on a gray line segment and clicks the mouse |
a)
The line changes
from gray to light blue. b)
The "player
turn" message changes to prompt Player 1 to play. |
7.3.1.2 |
|
3. Players alternate
turns as they select lines, according to their strategy. |
Fills in lines with
appropriate colors and alternates turns, as described above. |
|
|
4. After some number of turns (depending on
the game strategy), one of the players selects a line segment that makes the
fourth side of a square (Figure 2.1) |
a)
The gray square is
filled in with the color corresponding to the player who completed the
square. b)
That player's score
is increased by one. c)
The turn remains
with the player who completed the square. |
7.2.1.2.a 7.3.1.4 7.2.1.2.b |
Table 3.2 How to Select Lines and Score Points
The player keeps the turn as long as she continues to
complete squares, although he is not forced to complete available squares. The sequence of alternating turns until a
square is completed and a point is scored is shown in Figure 3.1.
|
|
|
|
|
|
After
One Move
After
Two Moves
After
Three Moves
Point
ScoredFigure 3.1 Line Selection Sequence to Score a Point
3.3 Winning
Players continue alternating turns until the game is won - or they decide to restart to a new game or quit the game. The game is won when there are no more squares that can be filled in. Figure 3.2 shows the final move of a game. After a game is won, the players can elect to start a new game, by pressing Restart (described in paragraph 3.5), or quit the game by closing the Dots & Boxes window (described in paragraph 3.6).
|
Player |
Dots and Boxes |
Req Para |
|
|
1. Player selects last unselected (gray) line
segment, which will also complete a square. |
a)
All actions
described above for coloring and scoring are executed. | ||