In the Learn to Play book and in the RRG on page 6 it discusses selecting Battle Cards by shuffling the whole deck and randomly dealing three cards from each deck.
However, I’ve seen in list builder apps where you select four Battle Cards from each deck you want to bring with your list.
I’ve looked in the Learn To Play, RRG and Tournament Regulations but I can’t find where rules say to select four Battle Cards Of each type with your list. Where can I find this?