Last session, I was running, as DM, the adventure from the Starter Set(Lost Mine of Phandelver) and one of the pregenerated characters is a Lightfoot Halfing Rogue with the Naturally Stealthy ability, which a player was using to hide during combat.
Naturally Stealthy. You can attempt to hide even when you are obscured only by a creature that is at least one size larger than you.(PHB p.28)
My problem is that I am confused as to what hiding means. Are you considered hidden only when you're stationary and/or behind some kind of cover or does it mean that even if you move, you're "lurking in the shadows" so you can still have the Unseen Attackers advantage?