Having your guest names printed directly onto the invitation will certainly clear up any confusion as to who is invited to your wedding. However if you feel it is not necessary to personalise each invitation, here's the other way to avoid awkward situations of people attending with an uninvited guest.
You can simply address the envelope with the names of your intended guests and hope that common sense is prevalent. Most times it gets the message across and if your guests are unsure they will contact you. Some couples add text such as "strictly invites only" or "no kids" to the RSVP. If you are inviting a guest that may bring a partner but you're unsure of their name, you can add "and guest" (although I personally think it's nicer to find out their name - especially if they are coming to your wedding!)
We provide the service of personalising your invitations with guest names so just let us know in the consultation if this is something you are after.