A Round Robin is a multi-person trading scheme.

The originator puts together a list of participants.

He sends a quantity of chips to the first person on the list.

That person goes through the chips looking for what chips they want and they take them, They put in one of their own chips for each chip they take out.

They then send it to the next participant and so on and so on until it returns to the originator.

Each RR has its own rules, but generally you can't put in a duplicate of a chip which is already there, chips are supposed to be of the same condition as the chips you remove. The RR might be limited to a specific type of chip such as roulettes or Nevada or Indian.

If done properly each participant should document what they took and what they left, unfortunately that usually doesn't happen.