How does Expertise work?
Bards get Expertise at level 3. How does this work?
For example, if I have a standard proficiency bonus of +2, and if I have proficiency in Perception with a Wisdom ability modifier of +2, then my Perception is +4. If I choose expertise in Perception, does it double the +4 to Perception +8, or does it double the proficiency bonus only to +4 for a total of Perception +6?
At 3rd level, you choose two of your skill proficiencies. Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies. (PHB p. 54)
What that is saying is that, if you choose Perception for one of your Expertise skills, your proficiency bonus is doubled, not the entire Perception bonus. You would indeed get a total of +6 to Wisdom(Perception) checks.