In a Round Robin each participant starts with a block which is passed around to team members who make additions to it based on instructions from the guild each month. The original block owner doesn't see the in-process quilt until the last team member has added to it.  However, team members may consult with other team members for ideas or advice.  Just keep it a secret from the maker of the original center block.  Here are the instructions for our 2019-2020 Round Robin.