It appears the event RSVP total for my event page is not accurate. The system is reporting 10 more RSVPs than have registered (I've also counted +1's ).
As you can see the system is reporting 42 total RSVPs with 10 "hidden" RSVPs. I've counted all of the RSVPs for the event and all of the +1's, there are only 32 total people registered. I have no idea why the system is reporting 10 hidden RSVPs.
Looks like you added some additional RSVPs for this event under Event settings > Basics > "Additional # of RSVPs to add to the total." This helps you track people you still need to collect information from at the door.
Complete and current information on how to use NationBuilder is available in the documentation section.