Connect 4: The rules of the game
To win a game a player must occupy four adjacent positions
in a horizontal, vertical, or diagonal line.
A player can occupy a position only if there is no empty position below it.
When the sprite is placed on a position that can be occupied,
the position changes color.
Players alternate in occupying positions.
The menu
Game
- Full/Random Board
By default, the board misses a few positions randomly selected.
It is possible to play with a full board, though.
Choose either Full Board or Random Board
to toggle between these two options.
- New Game
The behavior of this choice depends on both
the state of the game and the combination of players.
If the current game is terminated,
this choice resets the board and starts a new game
with the current combination of players.
If the current game is not terminated,
this choice resets the board and it starts a new game
where the human player playes first,
i.e., it waits for a human move.
- Quit
You may use this choice when your supervisor steps inside your cubicle.
If the program is executed as an application,
it terminates the program.
If the program is executed as an applet,
it simply closes the board window.
In this case, the game configuration is preserved and the game can be
resumed later.
To reopen the game window click on the applet.
Players
The game is intended to be played by a human against the machine.
However, it is possible to play both human against human
and machine against machine games.
The Players menu provides self-explaining choices for
all the possible combinations of player.
Note that the combination of players may be reset by a new game.
If New Game is selected when the current game is not
terminated, the player moving first of the new game is always
human regardless of the combination of players in effect
when New Game is selected.
Moves
Normally, one players makes a move after the other until the
game is terminated.
This menu allows a human player to change this order.
When the program waits for a human move, the player
can select one of the following options.
These options are no longer available after the game is
terminated.
- Backtrack moves
This choice backtracks a ply (a sequence of two consequetive moves).
The choice is enabled only after a ply has been made.
The chips removed from the board are blinked similar to when
they are dropped into the board.
After a ply has been backtracked, the game resumes normally,
i.e., the human can move or make any other choice available
in the current status of the game.
- Suggest move
This choice instructs the program to compute a move and
to blink the corresponding position.
No chip is dropped into the board.
After blinking the computed move, the game continues normally.
The human can make any legal move she likes.
- Force move
This choice allows the human player to replace the last move
with a move of her choice. Obviously this is cheating.
The replacement of the last move occurs in two steps.
First, the last chip dropped into the board is removed as in
backtracking. Then, the human player is expected to make a
move for her opponent. After this move is made,
the game continues normally, i.e., the human player makes
her own move.
Level
This menu is intended to define the quality of the machine move.
Levels at the top of the menu lead to fast move.
Levels at the bottom of the menu lead to supposedly better moves.
The underlying strategy, known as open line, is naive and no level
is very challenging. Some levels are interesting only
for very small children.
Help
This menu provides information about the program
(currently disabled by the jnlp protocol.)
Slovak
translation courtesy of
Margareta Sliwka.
Ukrainian
translation courtesy of
Sandi Wolfe.
Bosnian
translation courtesy of
Amina Dugalic.
French
translation courtesy of
Jean-Etienne Bergemer.
Czech translation courtesy of
Ivana Horak.
Comments, corrections and bug reports
to antoy@cs.pdx.edu.
Version 0.72, 6/12/2000.