Set up team entries in the Tickets & Pricing section of the Event Creator. Check the box marked Team under the sub event you want to run as a team event.
Setting team sizes
Checking the Team box opens team options on the left-hand side, including the minimum and maximum number of people in a team.
There is also a checkbox called Force minimum entries. If you tick it, the person entering must buy at least enough tickets to meet the minimum team size in one go. If you leave it unticked, a team can be started with fewer entries and filled later.
Offering discounts for larger teams
Select Yes from the Allow Bulk Entry Discounts dropdown. You can then set as many thresholds as you like, each with the discount that applies to a team of that size.
This works as an incentive. From the participant's side, gathering more people into their team earns them a bigger discount at checkout, so the discount does the recruiting for you.
The Team Hub
Each team gets its own Team Hub, where teammates can talk to each other and invite others to join.