This game I stumbled upon in a book of things to do when you are bored, and basically here you will post a topic, then go through the alphabet saying something that relates to the topic with the next letter in the alphabet. Ex:
Me: The topic is... Fruits
Person 1: Apples
Person 2: Bananas
Person 3: Cantaloupe
I think you get the Idea. When you get to Z the next poster will say the topic and it begins again! So the current topic is...
FRUITS
Edit: the topic CAN be something different. Dunno if I made sense about that being clear above or... whatever you get my point.