bearcubjay asked: How does Vax have plus double digits in proficiencies?

Let’s look at his expertise in Stealth. Since stealth is a Dex skill and his dex is 20, that starts him at +5. At level 12, his proficiency bonus is +4. As a level 12 rogue, he chose to use one of his four Expertise points in Stealth, doubling his proficiency bonus for it (+4 again). This brings him to 13 total for Stealth (it’ll be 15 at level 13!).