I was a drama geek in high school. I'm actually amazed that I didn't follow that into some kind of career in the theater (or film, natch) as an adult. One of the plays I worked on in high school was Ira Levin's Veronica's Room, which is one of those plays where you confine a small number of characters in a limited setting and play all kinds of games with their reality. There are other variants, including Levin's own Deathtrap, but this was my first encounter with them. 12 Angry Men is an upscale version, for one example, while the grandmother of them all is Agatha Christie's The Mousetrap. These kinds of plays are puzzle boxes, and the fun is in sorting through the clues left for the audience to see if you can stay ahead of the game. I thought about all of this while I was watching Exam (2009, directed by Stuart Hazeldine), which would work perfectly as a stage play. It, too, is a puzzle box. Almost literally.
The set-up is simple: Eight candidates for a lucrative job with a shadowy corporation are confined in a room and given an exam. The exam's proctor (Colin Salmon) issues a very precise set of instructions, and who succeeds and who fails depends on how carefully they can listen to and, importantly, interpret those instructions.