double double proficiency

[Camman1984]

if I have rogueish expertise in a skill, then I take a for example a feat that allows me to double my proficiency, would I get triple proficiency? I haven't seen anywhere that says it doesnt stack so maybe?

[RickAllison]

if I have rogueish expertise in a skill, then I take a for example a feat that allows me to double my proficiency, would I get triple proficiency? I haven't seen anywhere that says it doesnt stack so maybe?

It doesn't. From pages 173 and 174 of the PHB:


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.

So you can have Expertise, the Arcanist feat, and an Amulet of the Sphere (doubles Arcana proficiency for manipulating Sphere of Annihilation) and you would only have 2X the proficiency for the check, not 8X or anything like that.

[Camman1984]

that's the bit I couldn't find, so no stacking proficinecies to stick my stealth through the roof. although I was rolling d20+17 with advantage the other day to hide at level 5 so.i think I'm good :)

[Lonely Tylenol]

that's the bit I couldn't find, so no stacking proficinecies to stick my stealth through the roof. although I was rolling d20+17 with advantage the other day to hide at level 5 so.i think I'm good :)

How??? Are you being given an arbitrary +10 somewhere?

[MeeposFire]

How??? Are you being given an arbitrary +10 somewhere?

Probably pass without trace.

[Lonely Tylenol]

Probably pass without trace.

Oh, yeah, that would do it... Aaaaand a Ranger would have it by 5th level. Welp, I feel pretty silly now.

[RickAllison]

Through a combination of Expertise, a reward that was basically the Int Tome, and various magic items, my level 12 PC has a modifier of +17 for Arcana and Investigation, +12 for the other Int skills, and +10 to my Perception. One more level and that goes to +19, +13, and +11. And then I have Observant and the Sentinel Shield, so my passive Perception and Investigation are generally 30 and 32. If my DM okays the new feats from the Unearthed Arcana, I will have glorious passive checks of 37 on Perception and 34 on Investigation next level. Or maybe I will pick a different feat. Who knows.

The sad part is that the next highest Perception is significantly smaller than mine. I mean it is a pretty fair check, but our DM always gets a big grin whenever he notices that my PC isn't around to spot everything. Suddenly, all the invisible, Hiding, and illusion-using enemies come out in force.