There are already some pretty cool games for guessing linear relationships/regression lines. Dr. Hill's Eyeball Regression Game . The old, reliable Guess the Correlation game. However, I found a new one that has a particularly gorgeous interface, and a few extra features to help your learners. History of Data Science created the Regression game . It provides the player with a scatter plot, then the player needs to guess the y-intercept and slope. See that regression line? It is generated and changes as the entered a and b values change, which is a good learning tool. If played at the "easy-peasy" level, the player can even change those numbers multiple times over the course of 30 seconds, and watch as the corresponding line changes. I think this game is a nice way to break up the ol' regression lecture and allows students to see the relationship between the scatter plot and the regression line.