This was inspired by another improv game, with the instructions adapted from Bringyourimprov.
I imagine this primarily as a aural comprehension activity, with the teacher doing the narrating.
the students (or the teacher!) acts as the Narrator. They mime typing on a typewriter or computer, and pretends to read what they are typing out loud while typing. The students (who have been allocated roles before the start) act out what they hear. The Narrator can switch
to another location, introduce new character or add unexpected events.
Students who are not participating watch carefully, and could either act as prompts to help the actors, or could take over a character if an actor makes a mistake or doesn't demonstrate their understanding well enough.
Variation (from the original instructions)- When a scene goes bad, the Narrator can mime
ripping a couple of pages of his story apart, and restart the scene
(or the story).
Other ideas: If you have a dress-up box, then you could add descriptions of the characters, and students need to select the appropriate clothes to wear.
Provide props that they need to select when mentioned in the story, or perhaps there are a number of students who can be selected to be the prop.