diff --git a/yahtzee.py b/yahtzee.py
index 69b0e97..af6076c 100644
--- a/yahtzee.py
+++ b/yahtzee.py
@@ -5,12 +5,18 @@ class Yahtzee:
     This version of Yahtzee is initialized with a list of goals.
     """
     def __init__(self, goals):
+        """Initialize a Yahtzee game.
+        Sets the starting score to zero, stores the list of scoring goals,
+        and creates five Die instances to represent the player's dice.
+        """
         self.score = 0
         self.goals = goals
         self.dice = [Die() for num in range(5)]
 
     def play(self):
-        print("Welcome to Yachtzee!")
+        """Play an entire game of Yahtzee.After all
+        rounds are played, prints the final score."""
+        print("Welcome to Yahtzee!")
         self.score = 0
         for goal in self.goals:
             goal.used = False
@@ -19,6 +25,12 @@ class Yahtzee:
         print(f"Your final score was {self.score}")
 
     def play_round(self):
+        """Play a single round of Yahtzee.
+        Starts the round by resetting the number of rolls left to three and
+        rolling all five dice once. Shows the current status, lets the player
+        choose a goal or re-roll, marks the chosen goal used, and adds the
+        resulting score for that goal based on the current dice.
+        """
         print("=" * 80)
         self.rolls_left = 3
         for die in self.dice:
@@ -29,10 +41,12 @@ class Yahtzee:
         self.score += goal.score(self.dice)
 
     def show_status(self):
+        """Display the player's current game status, Builds a string with the current score"""
         dice = ', '.join([str(die) for die in self.dice])
         print(f"Score: {self.score}. Rolls left: {self.rolls_left}. Dice: {dice}.")
 
     def choose_goal(self):
+        """Let the player choose a goal or re-roll during a round."""
         options = []
         unused_goals = self.get_unused_goals()
         for goal in unused_goals:
@@ -49,6 +63,7 @@ class Yahtzee:
             return unused_goals[choice]
 
     def get_choice(self, options):
+        """Prompt the player to pick one of the provided options."""
         print("What would you like to do?")
         for i, option in enumerate(options):
             print(f"{i}. {option}")
@@ -59,6 +74,7 @@ class Yahtzee:
         return int(choice)
 
     def option_choice_is_valid(self, choice, options):
+        """Validate that the player's textual choice corresponds to an index."""
         if not choice.isdigit():
             return False
         if int(choice) < 0:
@@ -68,9 +84,11 @@ class Yahtzee:
         return True
 
     def count_unused_goals(self):
+        """Return the number of goals that haven't been used yet."""
         return len(self.get_unused_goals())
 
     def get_unused_goals(self):
+        """Return a list of goal objects that are not yet used."""
         unused_goals = []
         for goal in self.goals:
             if not goal.used:
@@ -78,6 +96,7 @@ class Yahtzee:
         return unused_goals
 
     def reroll(self):
+        """Perform a re-roll of selected dice."""
         self.rolls_left -= 1
         choices = self.get_reroll_choices()
         dice_to_reroll = self.get_dice_to_reroll(choices)
@@ -85,6 +104,7 @@ class Yahtzee:
             die.roll()
 
     def get_dice_to_reroll(self, choice_ints):
+        """Map a list of face-value integers to Die objects to re-roll."""
         dice_to_reroll = []
         for die in self.dice:
             if die.face in choice_ints:
@@ -93,6 +113,7 @@ class Yahtzee:
         return dice_to_reroll
 
     def get_reroll_choices(self):
+        """Ask the player which dice to re-roll and return a list of ints."""
         print("Which dice do you want to re-roll?")
         choices = input("> ")
         while not self.reroll_choices_are_valid(choices):
@@ -102,6 +123,7 @@ class Yahtzee:
         return choice_ints
         
     def reroll_choices_are_valid(self, choices_str):
+        """Validate the player's re-roll input string."""
         if not choices_str.isdigit():
             return False
         choice_ints = [int(digit) for digit in choices_str]