You can’t prosecute a successful war without some planning.
Sure, you could drive around with your boyz looking for trouble, relying on your luck to find someone to practice your tactical acumen on, but a bit of planning can make sure there is someone to shoot at.
The Emperor’s Tarot indicates the following dates have peak chances for mortal combat.
2016 is very lean so far:
November – Apocalypse
2017 is Arc40K; Arcanacon is turning 20 and is going to go off.