When you creep, you being trying to
Sneaking.
If you are not behind cover, this automatically fails, unless you have an ability or effect that nullifies this, as you are easily spotted out in the open.
After you click this ability, your
Sneak vs every
Enemy (or opposing) creature's
Attention within the encounter.
If successful, you being
Sneaking.
You slink through shadows, muscles taut, breath shallow. The rough stone wall grazes your fingertips. Each step is deliberate, silent on the cold floor, eyes scanning for enemies in the dim, flickering torchlight.