Wahapedia Core Rules -
Your opponent nods. You click the link to and see the rare rules note: "If both players have Fights First units, they alternate starting with the defending player."
You open Wahapedia on your phone. You type "Fight First" into the search bar (a feature that loads results as you type, faster than Google). It brings up the subheading: "Order of Combat."
You click . Another modal. It explains that if an Area Terrain piece is 5" tall, it blocks line of sight to models behind it unless the shooter or target is inside it.