Hangman Solitaire

Software Requirements Specification

 Functional Requirements    Nonfunctional Requirements    UI Prototype    Informational Requirements     Appendix

Executive Summary

Hangman Solitaire is a computer-based version of the classic two-player word game of the same name.  The human player competes against the computer to guess a word the program has selected at random.

General Description

Product Perspective

The benefit of this program is primarily that it allows someone to play as a solitaire game without requiring another person to participate.

Product Features

The application's purpose is to simulate the word game "Hangman."   The major features are:

User Characteristics

Hangman is designed for personal computer users who enjoy simple solitaire word games. Hangman is purely recreational software with little or no utilitarian value. The user is assumed to be competent using a WIMP interface (windows, icons, menus, pointers) to operate simple computer games such as Minesweeper or Klondike Solitaire.  The user is assumed to be familiar with the rules of Hangman. It is assumed the user knows how to start Java applications from the command prompt and provide command line parameters.

Assumptions and dependencies

Hangman is dependent upon the Hangman Word Server application. Word Server must be running in order for Hangman to obtain a hidden word to use for the game. Word Server can be running on the same computer, or on a remote computer in which case the computer running Hangman will need an active network connection to the remote computer.
Hangman uses hidden words in English.
Hangman assumes the words obtained from the Word Server are valid.
Scheduler will run on Windows 9x/XP and Linux platforms.

General Constraints

Hangman Functional Requirements

A. Starting the Application

Allow the user to enter on the command line the IP address of a remote computer that is running a Hangman Word Server.  If the user doesn't provide an IP address, use as a default the address "localhost."

At the start of each game the application will request a word from the Hangman Word Server specified by IP address.

The word obtained from the Word Server will be designated as the "hidden" word the player tries to guess.

If no connection can be made to a Word Server on the given IP address display an error message on the console "Apparently no hangman word server is running at <IP address>."

If a word is obtained from the Word Server, game play begins by offering the player their first turn.

B. Playing a game

At each turn the application will display a visual indicator of how many letters are in the hidden word and if any of the letters have been correctly guessed they are shown in the proper position in which they appear in the word.

The application will display a "guess count" which shows how many incorrect guesses the player has made.  An incorrect guess is guessing a letter which is not in the hidden word.

The application will allow the player to enter a letter.

If the letter entered is not between A and Z display a message "Invalid move" and allow the player to guess again (without penalty).

When the player enters a valid letter the application will check to see if the game is over and if not will continue to the next turn.

C. Ending a game

The player wins by correctly guessing all the letters in the hidden word.

The player loses if he/she makes seven incorrect guesses.

If the player wins the application will display a congratulatory message.

If the player loses the application will display a consolation message and will reveal the hidden word.

When the game is over (either win or loss) the application will offer the player an opportunity to begin another game.

If the player indicates they want to play again, a new game is started.

If the player indicates they do not want to play again, the application is terminated.

Note: there is no way for a player to request termination of play during the middle of a game.

Word Server Functional Requirements

Hangman Word Server runs as a stand alone application independently from the Hangman Solitaire game.

When a client program makes a network connection to the server's port the server will respond by sending a character string then closing the connection.

The character string will be randomly selected from a file of english words.

User Interface Requirement
When started, Word Server must display a message indicating the host address on which it is running, e.g.:

WordServer running on IP Address:

Hangman Non-Functional Requirements

General Guidelines: Performance and reliability are not very important.  Priority  should be given to adaptability, maintainability, and usability.

Operating Constraints

  1. The program requires the JRE v1.4 with Swing from Sun Microsystems.

Platform constraints

  1. The program requires a 486 or higher processor with 16 Megabytes of RAM and 5 Megabytes of available hard drive space.


  1. If it is desired to change the number of turns in a game, the developer will be able to make the required changes in < 1 person-hours.


  1. The user must be able to specify an alternate user interface at execution time on the command line.
  2. Any alternate user interface must be able to "plug in" at run time without recompiling the application.
  3. Any alternate user interface must implement the HangmanUI interface provided by Dr. Dalbey (see External Interfaces).


  1. A short (< 200 words) message explaining command line syntax should be displayed if the user enters no command line parameters.


  1. The program will run on Win 95/98/XP and Red Hat Linux 9.


  1. Since the program is purely for recreation and involves no user data, reliability is of low importance.


  1. The program will not access any user data files or programs.
  2. The program will not alter or replace any system files.


  1. A new user should be able to play a complete game of hangman in less than ten minutes.
  2. A new user should commit less than one error in use of the game (e.g. selecting the wrong letter) every ten minutes.
  3. A user who is familiar with the rules of Hangman be able to correctly operate the program without any written documentation.


  1. (optional) If the user provides an IP address of zero then skip getting a word from the Word Server and use a default word "calpoly" as the hidden word.


  1. The program is to be deployed as executable java bytecode files (".class" files) that must fit on a 1.2M flexible disk. They must use no specific java package.


  1. Desired Response Times (not critical) : At game start: less than five seconds

  2. After each turn: less than two seconds

Word Server Non-Functional Requirements


  1. After receiving a request, the word server must respond in less than half a second.


  1. It is desirable that the game administrator be able to modify the words data file using a simple text editor.
  2. Adding a new word to the word data file should take less than ten minutes.

Behavioral Requirements

UI Prototype

Informational Requirements

Data Model

Data Flow Diagram
  name guess count
  alias turn count
  description The number of incorrect guesses the player has made this game.
  definition 0 <= guess count <= guess limit
  supplementary  none
  name guess limit
  alias none
  description the number of guesses a user is allowed before they lose the game.
  definition guess limit = 7
  name hidden word
  alias secret word
  description the word the player is trying to guess
  definition hidden word = { alphabetic character }30
  name guessed word
  alias none
  description the letters that the player has correctly guessed, in their proper position in the word.
  definition guessed word = { alphabetic character }30
  name continue choice
  alias none
  description whether the user wants to play again or not
  definition continue choice = {y | n }



IP address
internet protocol address: the location of a computer on the internet (may use the domain name).
acronym for User Interface

Error Handling

Included in functional requirements.

File Formats

The word server data file is a plain text file that contains one word per line with no leading, trailing, or embedded blanks.

External Interfaces

The Hangman Solitaire game and the Word Server will communicate via standard internet socket communication.

The design of the user interface to the Hangman Solitaire game must conform to the HangmanUI interface provided by Dr. Dalbey.

Engineering Analysis

Platform Choice (O/S and Language)
Java was chosen because the CSc dept computer labs support both Windows and Linux operating systems and students may want to deploy the application on different platforms.  Performance is not a big concern as the application is a simple word game without heavy computational demands, and the slower performance of Java is acceptable to gain its portability advantages.

Distributed Architecture
Separating the application into the game and server components allows the word server component to be used with other applications.

In the future it is quite likely that developers may want to create a different user interface for the game. To simplify this task, the user interface is separate from the game logic. Additionally, the interface to which the UI design must conform is made public to allow third party developers to create their own front end to our game.


Document History
Date Author Change
9/26 JD limited word length to 30 in data dictionary
9/20 JD Initial Release