I played a review game with my geometry class a few weeks ago that they loved so I thought I'd share it. I think I stole this idea from a blog, but I can't for the life of me remember which blog, so if it's yours let me know.
I stole the problems from the Pearson Geometry Common Core Edition.
I printed the document below double sided but didn't staple it. Then I shuffled the pages and made 8 or so copies of all of them for the 8 groups in my class. The groups needed to start with the page that has "RP" at the top and do the proof. Then they hunt for the answer in the sheaf of papers. When they find the answer, they grade their proof against the answer key, turn the answer key over and work the problem on the back of the answer key. Then they hunt out the answer key to the new problem.
If they keep track of the order in which they did the problems, they can write down all the letters from the upper right hand corners of the problems, unscramble them and a message appears.
I had students for the first time actually paying close attention to every step of the proof, asking great questions about why different steps appeared, if they were necessary, and if/how order in the proof matters. They also really loved working out the code.
I know it's just drill and kill two-column proofing, but it did a nice job of getting my students to compare different proving methods and getting them to analyze their own work.
Here it is: