Black Box is a game of "hide and seek

Hide and seek

Hide-and-seek or hide-and-go-seek is a variant of the game tag, in which a number of players conceal themselves in the environment, to be found by one or more seekers.-Variants:Numerous variants of the game can be found around the world...

" for one or two players, which simulates shooting rays into a black box to deduce the locations of atom

Atom

The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...

s hidden inside. It was created by Eric Solomon. The board game

Board game

A board game is a game which involves counters or pieces being moved on a pre-marked surface or "board", according to a set of rules. Games may be based on pure strategy, chance or a mixture of the two, and usually have a goal which a player aims to achieve...

 was published by Waddingtons

Waddingtons

Waddingtons was a publisher of card and board games in the United Kingdom. The company was founded by John Waddington of Leeds, England and Wilson Barratt, under the name Waddingtons Limited...

 from the mid 1970s and by Parker Brothers

Parker Brothers

Parker Brothers is a toy and game manufacturer and brand. Since 1883, the company has published more than 1,800 games; among their best known products are Monopoly, Cluedo , Sorry, Risk, Trivial Pursuit, Ouija, Aggravation, and Probe...

 in the late 1970s. There are also numerous computer implementations for many different platforms, including one which can be run from the Emacs

Emacs

Emacs is a class of text editors, usually characterized by their extensibility. GNU Emacs has over 1,000 commands. It also allows the user to combine these commands into macros to automate work.Development began in the mid-1970s and continues actively...

 text editor

Text editor

A text editor is a type of program used for editing plain text files.Text editors are often provided with operating systems or software development packages, and can be used to change configuration files and programming language source code....

.

Black Box was inspired by the work of Godfrey Hounsfield

Godfrey Hounsfield

Sir Godfrey Newbold Hounsfield CBE, FRS, was an English electrical engineer who shared the 1979 Nobel Prize for Physiology or Medicine with Allan McLeod Cormack for his part in developing the diagnostic technique of X-ray computed tomography .His name is immortalised in the Hounsfield scale, a...

 who was awarded the 1979 Nobel Prize in Medicine for his invention of the CAT scanner. Its theme has always been abstract.

Object of the game

Black Box is played on a two-dimensional grid. The object of the game is to discover the location of objects ("atoms", represented by metal balls in the Waddingtons game and by yellow balls in the Parker Brothers version) hidden within the grid, by the use of the minimum number of probes ("rays"). The atoms are hidden by a person in a two-player game. In a solitaire game, they are either hidden by a computer or they are pre-hidden; in this case, the results of various probes are resolved by looking them up in a book. The seeker designates where the ray enters the black box and the hider (or computer or book) announces the result (a Hit, Reflection, or Detour/Miss). This result is marked by the seeker, who uses these to deduce the position of the atoms in the black box.

Rules

The most common configuration for novice players is four atoms in an 8-by-8 grid. At left is a sample black box in this configuration.

There are 32 input positions in an 8-by-8 grid, eight each at the top, bottom, right, and left. A beam is "fired" into one of these positions and the result is used to help deduce the location of a known number of hidden atoms.

Hit

Atoms interact with rays in three ways. A direct impact on an atom by a ray is a "hit". Thus, ray 1 fired into the box configuration at left strikes an atom directly, generating a "hit", designated by an "H". A ray which hits an atom does not emerge from the box.

Deflection

The interaction resulting from a ray which does not actually hit an atom, but which passes directly to one side of the ball is called a "deflection". The angle of deflection for this ray/atom interaction is 90 degrees. Ray 2 is deflected by the atom at left, exiting the box as shown.

Reflection

The final type of interaction of a ray with an atom is a "reflection", designated by an "R". This occurs in two circumstances. If an atom is at the edge of the grid, any ray which is aimed into the grid directly beside it causes a reflection.

Rays 3 and 4 at left would each generate a reflection, due to the atom at the edge. Ray 5 would be a hit on the atom.

Double deflection

The other circumstance leading to a reflection is when two deflections cancel out. In the grid at left, ray 6 results in a reflection due to its interaction with the atoms in the grid.

Miss

There are also misses. Ray 7 at left, for instance, interacts with no atoms in the grid.

Detour

Rays that don't result in hits or reflections are called "detours". These may be single or multiple deflections, or misses. A detour has an entry and an exit location, while hits and reflections only have an entry location for a hit, and a single entry/exit location for a reflection.

Of course, more complex situations result when these behaviors interact. Ray 8 results in two deflections, as does ray 9.
Some rays travel a twisted course, like ray 1 at left.
Notice that this complex set of five deflections above looks exactly like a single deflection, as shown by ray 2 at left. Things are not always as simple as they seem within a black box.
Reflections and hits can be more complex, too. Ray 2 gets deflected by the first atom, reflected by the next two atoms and again deflected by the original atom, yielding a reflection.
Ray 3 below gets deflected by the first atom, then by the second atom, and then hits the third atom, yielding a hit.
The complete set of interactions of rays with the original sample black box is shown at left. Note that for detours, the input and output locations are interchangeable - it does not matter if ray 2 below enters the box from the left side, or the top.

Scoring

Each entry and exit location counts as a point. Hits and reflections therefore cost one point, while detours cost two points. When the seeker guesses the location of the atoms in the grid, each misidentified atom position costs penalty points: ten in the original Waddingtons rules, five in the Parker Brothers version and most computer editions.

Different atom positions lead to different average scores - a very easy four-ball game might average eight or nine points to solve, while a very hard game might average 18 points.

Variants

The most common variant of Black Box is played on an 8-by-8 grid with five (or more) atoms. Five-atom configurations allow for positions that cannot be unambiguously determined by probes. The grid at left shows an example of this.

If the fifth atom is in any of the four positions marked by the X, no ray can ever determine where it is located, because it is shielded from all directions by the surrounding atoms. The addition of more atoms allows for more complex indeterminate configurations, but also allows for more intriguing interactions.
It is possible to "hide" a ball with this four-atom configuration.

It is not ambiguous, however.

Black Box can also be played with different-sized grids, such as 10-by-10 or 12-by-12 grids.

A related class of computer puzzle game

Computer puzzle game

Puzzle video games are a genre of video games that emphasize puzzle solving. The types of puzzles to be solved can test many problem solving skills including logic, strategy, pattern recognition, sequence solving, and word completion....

s feature different types of obstacles concealed in the box, which affect rays in varying ways — such as mirrors which reflect only a direct-hit ray, or prisms which split one ray into two. The GNOME

GNOME

GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

 game GFingerPoken and one section of the Macintosh game System's Twilight

System's Twilight

System's Twilight: An Abstract Fairy Tale is a graphical interactive fiction computer game created by Andrew Plotkin in 1993.- Summary :The game is a combination of puzzle and story, combining several different kinds of logic puzzles and word puzzles. The puzzles include variations of Set and Black...

fall into this class.

External links

• Downloadable version of the Black Box game
• Black Box on BoardGameGeek
  BoardGameGeek
  BoardGameGeek is a website that was founded in January 2000 by Scott Alden and Derk Solko as a resource for the board gaming hobby. The database holds reviews, articles, and session reports for over 45,000 different games, expansions, and designers. BoardGameGeek includes German-style board games,...