This easy game has worked well to re-enforce how to use the ablative case. To play it you need two teams, little whiteboards and markers. You also need two small objects to hide in your room. I used two plastic spiders but anything that fits in your hand should work. To play, send a representative from each team out of the room. Then, with the help of the class, hide the two objects somewhere in the room. Hide them in different places. Afterwards, everyone in the class writes a prepositional phrase to describe where each object is: sub mensa, a sella, a Iano (by my poster of Janus) in armario, etc.
Next, call the two students back in and using the directions from the rest of the class on the white boards, students look for the objects. When a student find the object, they win a point for their team. Now send two different students out and repeat the process.
This game is a hit in my class because everyone has task, no one is simply waiting for a turn. Students are either describing or looking for the objects. It works well to help cement the idea that prepositional phrases tell the reader "where" something is located. It has a 20-30 minute run time.
Tips to make this game work: