| yellowpete |
In a sense you kind of become Hidden when you act (but not literally).
Enemies can choose to target the square from which they detected the effects of your actions to originate, and if you're actually still there, you get targeted as you would if you were Hidden (DC 11 flat). So you want to use at least one action each turn on something that isn't detectable (whether moving or otherwise), that way they can never be sure if you've moved or not and are thus unlikely to gamble on hitting you.