I've gone into the game's default progression.xml, and looking at "perkLockPicking" we can see this:
<passive_effect name="LockPickTime" operation="perc_subtract" level="1,3" value=".17,.375"/>
Rank 1 = .17
Rank 2 = .2725
Rank 3 = .375
Now looking at the game's tooltip / description for the perk we see this:
Rank 1 ="You can pick locks 20% faster"
Rank 2 ="You can pick locks 40% faster"
Rank 3 = "Pick locks 60% faster"
I went ingame, and tested each rank, including default (Rank 0) and got these values:
(NOTE: Testing on 4 Different Locked Gunsafes, different gunsafe due to starting a lockpick session seems to have issues when adding points)
Gunsafe #1, at Rank 0: 20 Seconds
Gunsafe #2, at Rank 1: 16.5 Seconds
Gunsafe #3, at Rank 2: 14.5 Seconds
Gunsafe #4, at Rank 3: 12.5 Seconds.
Ok so going from Rank 0 to Rank 1 (supposed to be 20% Faster) we go from 20 Seconds, to 16.5 Seconds (which is 17% or .17, which is in line with the Rank 1 code)
Going from 20 Seconds to 14.5 Seconds is 27.25% Faster, ( .2725 when referencing the code for Rank 2)
Going from 20 Seconds to 12.5 Seconds is 37.5% Faster, ( .375 when referencing the code for Rank 3)
My Conclusions:
#1: The Description/Tooltip is a typo, and should read:
Rank 1 = "You can Pick Locks 17% Faster"
Rank 2 = "You can Pick Locks 27.25% Faster"
Rank 3 = "You can Pick Locks 37.5% Faster"
#2: The code for the passive_effect needs updating:
<passive_effect name="LockPickTime" operation="perc_subtract" level="1,2,3" value=".2,.4,.6"/>
#3: I'm an idiot, and I'm missing something here.