I had a PC who wanted to cast Charm Person on the king. I'm like, okay, let's think this through. In the same room as the king, we've got the archwizard of the university, the dean of the socerer/bard college, the head of the druid circle, and a bishop from the cathedral, all of whom are familiar with magic. Charm Person has both verbal and somatic components so if you cast it someone is going to notice it. You can make a Deception roll to cast the spell without anyone noticing you if you'd like. The PC decided against charming the king.