Group yourself into threes and choose a game.
Take a few minutes to familiarize yourselves with the rules of the game. If some members of a group already know the game then they should explain it to the other members of their group. Rules of games can be found online at www.pagat.com (card games), or Wikipedia.
Choose two members of your group to play the game. The other member will act as the recorder. While the two players play, the recorder should write down the actions of each player. It is not necessary for the recorder to write down the specfic outcomes of the actions: "the first player rolled the dice" will suffice without noting what the result of the roll was.
Play and record for about five minutes, or until there are no new kinds of actions to record. At the end of five minutes, write down everything you would need to know if you wanted to resume the game at exactly the same point later on. Write down this data using only numbers and characters. Put the pieces away neatly when you are done with this step.
All three members of the group should now participate in object oriented analysis of the game. Identify classes by finding nouns in the recorded transcript of game play. Identify actions by finding verbs (not all nouns or verbs will necessarily become classes).
For each piece of data, determine which of your classes that data belongs to. For each action, determine which of your classes that action is most closely associated with. Since actions may be associated with many classes it may be helpful to examine the data that affects or is affected by the action; the action likely belongs to the class whose data is most relevant.
Draw a simple UML diagram for your classes. Each class in your UML diagram should be represented by a box with three sections: one for the name of the class, one for the data, and one for the actions. Draw lines connecting classes to show associations. Extra Credit:: label the ends of the lines according to the multiplicity of the association and identify which associations are "is a" associations by adding a triangular arrowhead at the end (if A is a B then the arrowhead points to B).
If time permits, repeat for another game. If your previous game was a card game, choose a game that is not a card game. If your previous game was Yahtzee or Kismet, choose a game that is not Yahtzee or Kismet. Change the recorder for each new game.