Open your invitation design and select RSVP Settings at the bottom. From there, you can control two things:
- Allow Maybe responses. Guests can select Maybe when responding. If you turn this off, guests can only reply yes or no.
- Allow +1s. Set the maximum number of additional guests each guest can bring. If you set it to 0, guests won't be able to add anyone; if you set it to 2, they can say they're bringing up to 2 additional guests, and so on.