Question concering class abilities

[samduke]

Both the Rogue and Bard classes get Expertise. which allows another addition of the proficiency bonus on 2 skills.
Now presume your PB:=4 and proficiency skill was stealth & perception at a base of 5 ( attribute at 20 ). this base gives them each 9 for the first Expertise +4 for 13 each.
the second iteration of expertise does not say it can not stack nor be used on skills already selected ( near as I have seen ) so that 13 should get another +4 for 17 each.

question is this by the rules legal and if not will you please point to the book(s) and page(s) and errata if it applies.

thanks

[SethoMarkus]

Page 77 of the SRD (on mobile, not sure for PHB), under "Proficiency Bonus":


"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."

Emphasis mine.

[Millface]

yep, +13 is about as high as it goes. Still, a Half-Elf Bard/Rogue is double proficient in 4 things and proficient in tons of others. Difference between 17 and 13 is not alot, most DCs are well under 20.

[Citan]

Both the Rogue and Bard classes get Expertise. which allows another addition of the proficiency bonus on 2 skills.
Now presume your PB:=4 and proficiency skill was stealth & perception at a base of 5 ( attribute at 20 ). this base gives them each 9 for the first Expertise +4 for 13 each.
the second iteration of expertise does not say it can not stack nor be used on skills already selected ( near as I have seen ) so that 13 should get another +4 for 17 each.

question is this by the rules legal and if not will you please point to the book(s) and page(s) and errata if it applies.

thanks
I'm pretty sure it does not stack, but cannot remember the PHB rule or errata that clarifies it though. :/

[Christian]

The rule quoted from the SRD is from Chapter 7 of the PHB, on pg. 173, third paragraph under the Proficiency Bonus heading. It's not an errata or correction--it appears in my first printing copy.