Heroes of Loot

A random pick up is a cloak of invisibility. Once collected, enemies stop chasing after you. I found these only in 'secret' rooms. They are accessed by walking through a wall, into a second room. Often as you clear a dungeon you will see these secret room, as they are filled with collectibles. Not all dungeons have secrets but they are also not rare. Finding or buying the "Lens of Secret" will display these from a distance but you will likely stumble across one naturally. Not all secret rooms contain a cloak but again these are not rare enough that you won't come across one as you progress.