Use Case 1--Play Game (Move Pac Man)

Context of Use:
The User wants to move the Pac Man icon around the board in order to collect all of the dots and avoid the ghosts
　

Scope:
J2ME Pac-man Game Application
　

Level:
System Goal
　

Primary Actor:
The User
　

Stakeholders and Interests:
User: Wants to complete the level by moving Pac Man.
　

Preconditions:
The User has chosen to begin a game or continue a saved game and the game has been initialized.
　

Minimal Guarantees:
The User will be able to make another movement choice after the current one.
　

Success Guarantees:
Pac Man is moved in the direction that the User entered.
　

Trigger:
The User pushes the “Up” button to move Pac Man up, the “Down” button to move Pac Man down, the “Left” button to move Pac Man left, or the “Right” button to move Pac Man right
　

Main Success Scenario:
　

• 1. The User pushes one of the movement buttons.
  　
• 2. The Pac Man icon moves in the direction that the User entered.
  　
• 3. The Pac Man icon continues to move in the same direction until Extension 2a is reached.
  　

Extensions:
　

• 0a. An exception is thrown while getting the User input.
  　
  • 0a1. Catch exception and continue listening for future User inputs.
    　
• 1a. A ghost icon of Color 1 moves into the space where the Pac Man icon is before the User inputs a movement command.
  　
  • 1a1. A message is displayed saying that the current turn is over.
    　
  • 1a2. The number of lives is decremented and game is ended if number of lives reaches zero. (See End Game Use Case)
    　
• 2a. The User tries to move the Pac Man icon into a space that has a wall.
  　
  • 2a1. The Pac Man icon does not move and the program continues listening for future User inputs.
    　
• 2b. The User tries to move the Pac Man icon into a space that has a dot in it.
  　
  • 2b1. The Pac Man icon successfully moves into the space.
    　
  • 2b2. The dot is removed from the GUI.
    　
  • 2b3. A score of 10 points is added to the total score and updated on the screen.
    　
• 2c. The User tries to move the Pac Man icon into a space that has a super dot in it.
  　
  • 2c1. The Pac Man icon successfully moves into the space.
    　
  • 2c2. The super dot is removed from the GUI.
    　
  • 2c3. A score of 50 points is added to the total score and updated on the screen.
    　
  • 2c4. The ghost icons change to Color 2 and they are routed away from the Pac Man icon.
    　
  • 2c5. After 15 seconds, the ghost icons are changed back to Color 1 and routed towards the Pac Man icon.
    　
• 2d. The User tries to move the Pac Man icon into a space that has a ghost in it that is Color 1.
  　
  • 2d1. A message is displayed saying that the current turn is over.
    　
  • 2d2. The number of lives is decremented and game is ended if number of lives reaches zero. (See End Game Use Case)
    　
• 2e. The User tries to move the Pac Man icon into a space that has a ghost in it that is Color 2.
  　
  • 2e1. The Pac Man icon successfully moves into the space.
    　
  • 2e2. The ghost is removed from the GUI.
    　
  • 2e3. A score of 100 times the number of ghosts of Color 2 captured is added to the total score and updated on the screen.
    　
  • 2e4. A new ghost icon of Color 1 is added to the middle of the screen.
    　
• 3a. The Pac Man icon moves into a space that doesn’t have a wall and is on the edge of the screen.
  　
  • 3a1. The Pac Man icon is moved to the corresponding space without a wall on the opposite side of the screen.
    　

Technology and Data Variations:
None.