"Activity" vs. "Game"

As I read about games in the virtual and physical world, and ruminate on my upcoming presentation, I started to wonder what determines if something is an "activity" or a "game." Most good instructors come up with great activities for the classroom, and some of them are very engaging. But what pushes an activity that extra inch to become a "game"?

Just as I clearly formed that question in my brain, I came across Jesper Juul's definition of a game in Karen Collins' Game Sound: An Introduction to the History, Theory, and Practice of Video Game Music and Sound Design. His definition includes:

1. Rules
2. Variable & quantifiable outcomes
3. Player exerts effort to influence outcome
4. Player feels emotionally attached to the outcome

I think the first three parts could describe an activity or a game, but it is the last one that distinguishes between the two. Engaging students mentally is one thing, we should all try to do that. But sometimes I think we will want to engage them emotionally, to make them feel a strong desire to do well. And that makes a game.