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.