Joining or Creating a Team
Teams can have a maximum of four people, and all must be WWDC18 attendees. If you start a team but don't have a total of four people, you'll get a notice to invite more WWDC18 attendees. You can invite as many attendees as you would like, and the first three to respond will be on your team.
If you choose to be assigned to a team, you'll either be placed on an existing team or be placed on a new Free Agent team. If you are the first person on a Free Agent team, you'll be assigned the administrator role. Administrators get to choose the team name and team picture.
If your team has less than four people once the challenge starts, you can still participate but won't earn as many team bonus points when all team members close their rings.
Changing or Leaving a Team
As long as the challenge is open, you can change teams. However, if you leave a team you will lose all of the team bonus points that you earned with that team. To leave a team, open the Challenges app on iPhone and tap the name of the team you'd like to leave. Then, tap the arrow icon in the top right corner of the screen.
You will not be able to remove someone from your team. However, you can leave your current team, start a new team and mark it as "Invite Only" so that only people you invite can join.