I was initially inspired by from a drama / improvisation game as explained at bringyourownimprov called Alphabet, but this is quite a way removed from that original idea.
Divide the group into two teams. The teams are each given a person's name (e.g. Jono and Sani) and line up facing each other. Each team IS that person.
The first member of the first team (Jono) begins the game by starting a conversation (e.g. "Good morning sir, can I help you?").
The first member of the second team (Sani) responds (e.g. "Good morning, yes, I'd like to buy a shirt.")
then, the second member of the first team continues the conversation as if they were the first person (Jono).
next, the second member of the second team (Sani) responds, and so on until someone can't continue the conversation, or says something that doesn't make sense given the rest of the conversation, or repeats something that has already been said (unless they make it clear that this is deliberate - e.g. "what size was that again, sir?").
The idea is that they need to listen to what comes earlier, and answer questions appropriately and use the information that has already been given in the conversation.
Alternatively, it could be a story instead of a conversation, and could just go around a circle rather than having teams. (the teams just make it clearer for the conversation as to who is who, if that makes sense!)
If you have a class with a lot of experience with oral practice that can be relied to get on with using the target language without constant monitoring, or if you have an assistant in the room, you can divide the class up into 2 or 3 groups which are then divided into teams. It would also work you are using the peg system of encouraging target language use, or appoint "TL use monitors" who give out points for people using the TL, or take them away for using English (or their background language).
To get everyone involved for the whole time (beyond just listening carefully) you could get the whole team to do appropriate actions for that person. (e.g. holding out hand to shake when the first person introduces themselves, or in the shopping for a shirt example, holding up shirts to select from, or trying on the shirt ... depending on the character).
To make it harder (e.g. for upper school classes), I'd go back to the improv game that inspired this - I've copied the instructions below.
This is a scene consisting of 26 lines of dialogue. The first line
starts with a given letter (say `R`). The reply to that line must start
with a `S`, and so on, until the whole alphabet has been covered. After
`Z` comes `A`. Players that hesitate, use the wrong letter, uses random
words or does not move along the scene are replaced by another player.
This could be done as per the original, or as the team version I've described.
I'm going to be looking into improv games that I can adapt over the next few weeks, so hope to have some more ideas to share soon! Please drop me a line or write a comment if you have other game ideas, or to let me know what you think of this activity!
I'm off to go play pass the parcel with my Year 7s - have a great day!