All kids <18 may attend the kids' track and activities or the adult track with their badge. Older kids may find there are other activities in the adult track and they still need a guardian while at the event for liability reasons.
Any kid <18 needs a guardian with them at all times. This does not need to be a parent, but it cannot be a volunteer. You may have another parent who you designate on your waiver as a secondary guardian.
Guardians do not get badges or t-shirts. They cannot attend talks. They can stay in the area watching their kids in the kids’ track. If the kid wants to see a talk, which is absolutely fine and encouraged, the adult needs a full conference pass.
How to do this? You would buy an adult ticket and a child only ticket. Then each of you has a badge that will get you wherever you want to go. Now the adult also gets a t-shirt, swag, entry into the raffles (which are some AWESOME prizes) and admission to the afterparty, with food and open bar. Much more value than what you pay for any of these tickets. Plus, there are lots of discount codes floating around (i.e. Facebook and Twitter!)
Hope to see you and hope this all makes sense!