Vesper Primer+Skill Checks+Skill Mastery

The rogue becomes so confident in the use of certain skills that she can use them reliably even under adverse conditions. The rogue selects a number of skills equal to her Intelligence modifier. When making a skill check with one of the selected skills (or any of the skills selected through the rogue’s edge class feature), she can take 10 even if stress and distractions would normally prevent her from doing so. A rogue can gain this special ability multiple times, selecting additional skills for skill mastery to apply to each time.