Classes and responsibilities:

Game logic (1)

• Keep track of the players' turns
• Determine a winner
• Execute a turn and the correct number of turns

Player (2)

• take a turn
• make a decision on what category to score a roll

Scorecard (1 per player)

• keep track of open and scored categories
• determine how many points to award for a given roll

Dice (5 per player)

• Roll itself
• Report what number was rolled

Composition: HAS-A relationship

Game: contains 2 players

Player: contains 1 scorecard and 5 dice

Single responsibility principle: "classes should have a single reason to change"

(analogous to the "single layer of abstraction" within a function or method)