Check the "Register multiple participants" checkbox to allow users to register themselves AND additional participants for an event. When this feature is enabled, users have the option to specify the number of additional participants they are registering for. If this is a paid event, they can select a different event fees for each participant – and will be charged the total of those fees. If a profile is included – they will complete the profile information for each participant.

Allow multiple registrations from the same email address
Check this box to allow a user to register multiple participants using the same email address. If you want additional participants to be registered without requiring an email address to be entered for each person – check the "Register multiple participants" option, AND include a profile in this registration form which includes First Name and Last Name fields.
Fee label
Use the table to enter descriptive labels and amounts for up to ten event fee levels. These will be presented as a list of radio button options. Both the label and dollar amount will be displayed.
The spelling and capitolization must be as shown below.

You can also add additional fee categories to be used on the backend, but they will be hidden for the online registration.