Woo-Hoo, even though my mage has a magical aptitude of 99 he at last managed to spot a trap this morning whilst I was exploring the Ancient Temple. <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />
It's based on your Perception. Get your Dexterity high enough and you'll notice yourself dodging even without any points in the skill.
Arcanum is complex, wonderful, and mysterious. <img src="/ubbthreads/images/graemlins/up.gif" alt="" />
