Half scripted scene, First rehearsal scene.
In this scene one actor will read all her lines from a script, while the other actor must justify those lines and a scene will arise from this chaos.
One actor reads from a script, preferably a mundane high school like text, and takes all her lines from the script. She may read from one character, or several characters, whichever allows her responses to be quicker. The reader can help t he justifier by offering emotion and activity to the words. Trying hard to maintain a reality in the scene makes it the most fun, simply hacking on the reader as being crazy is a lazy wimpy way out.
The reader can launch into long texts, the justifier can ask the reader to repeat something (of course they cannot), accidentally reading stage directions.
Multiple scripts with or without an actor justifying