Level 10 Bard Expertise, can it double double?

[MarkVIIIMarc]

I have a Lore Bard advancing to level 10 and I would like to confirm how the Level 10 Expertise works.

Essentially, am I correct I must choose ANOTHER two skill proficiencies meaning I could not have picked Performance for my Level 3 Expertise and then double my proficiency in Performance again at Level 10.

Here is how it reads:
Expertise At 3rd level, choose two of your skill proficiencies. Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies.


At 10th level, you can choose another two skill proficiencies to gain this benefit.

[ProsecutorGodot]

Correct, it must be a different skill.

Regardless of whether you could choose the same skill, you can only apply a modifier that would increase/decrease it once:

Occasionally, your proficiency bonus might be multiplied or divided (doubled or halved, for example) before you apply it. For example, the rogue’s Expertise feature doubles the proficiency bonus for certain ability checks. If a circumstance suggests that your proficiency bonus applies more than once to the same roll, you still add it only once and multiply or divide it only once.

[RickAllison]

Nope!


If a circumstance suggests that your proficiency bonus applies more than once to the same roll, you still add it only once and multiply or divide it only once.

You only get to multiply it once. I found this out when I wanted to use to use the Talisman of the Sphere to be super-capable with a Sphere of Annihilation.

[BarneyBent]

Nope!



You only get to multiply it once. I found this out when I wanted to use to use the Talisman of the Sphere to be super-capable with a Sphere of Annihilation.

Happily, a level 13 Rogue with 20 INT and either the Talisman or Expertise in Arcana cannot fail an Arcana check to control a Sphere or Annihilation due to Reliable Talent. They might fail a contest against another creature though. “Enhance Ability” would provide some decent protection against that.

[RickAllison]

Happily, a level 13 Rogue with 20 INT and either the Talisman or Expertise in Arcana cannot fail an Arcana check to control a Sphere or Annihilation due to Reliable Talent. They might fail a contest against another creature though. “Enhance Ability” would provide some decent protection against that.

The highest Arcana in the Monster Manual are the Lich with +18, the Gynosphinx with +14, and Arcanaloths and Archmages at +13, then Ancient White Dragons at +11. This leaves a bit more room for error than I would like, but admittedly it's not a lot of creatures that can threaten it.

[bid]

Also note that in most other systems, doubling is actually +100%. So double double is triple.