The single best way to understand the game, of course, is to see it being played. This is taken from the play (dialogue is slightly altered in the movie, and is spaced out here between points for readability):

ROSENCRANTZ: We could play at questions.
GUILDENSTERN: What good would that do?
ROS: Practice!
GUIL: Statement! One-love!

ROS: Cheating!
GUIL: How?
ROS: I hadn't started yet!
GUIL: Statement. Two-love.

ROS: Are you counting that?
GUIL: What?
ROS: Are you counting that?
GUIL: Foul! No repetitions. Three-love. First game to--
ROS: I'm not going to play if you're going to be like that.

GUIL: Whose serve?
ROS: Hah?
GUIL: Foul! No grunts. Love-one.

ROS: Who's go?
GUIL: Why?
ROS: Why not?
GUIL: What for?
ROS: Foul! No synonyms. One-all.

GUIL: What in God's name is going on?
ROS: Foul! No rhetoric! Two-one.

GUIL: What does it all add up to?
ROS: Can't you guess?
GUIL: Were you addressing me?
ROS: Is there anyone else?
GUIL: Who?
ROS: How would I know?
GUIL: Why do you ask?
ROS: Are you serious?
GUIL: Was that rhetoric?
ROS: No.
GUIL: Statement! Two-all. Game point.

ROS: What's the matter with you today?
GUIL: When?
ROS: What?
GUIL: Are you deaf?
ROS: Am I dead?
GUIL: Yes or no?
ROS: Is there a choice?
GUIL: Is there a God?
ROS: Foul! No non-sequiturs, three-two, one game all.

GUIL (seriously): What's your name?
ROS: What's yours?
GUIL: I asked you first.
ROS: Statement. One-love.

GUIL: What's your name when you're at home?
ROS: What's yours?
GUIL: When I'm at home?
ROS: Is it different at home?
GUIL: What home?
ROS: Haven't you got one?
GUIL: Why do you ask?
ROS: What are you driving at?
GUIL (with emphasis): What's your name?!
ROS: Repetition. Two-love. Match point to me.

GUIL (siezing him violently): WHO DO YOU THINK YOU ARE?
ROS: Rhetoric! Game and match!