I like to give some variety to locks and traps, to make things a little more interesting than the old "ok, roll to unlock/disarm it". While intricate detail of the workings of the device is overkill in most cases, I found that a simple system to differentiate the quality of various devices doesn't slow things down too much. Here's what I came up with.
|Lock/Trap Quality||Open Locks and Remove Trap Adj.||Notes and probability|
|Shoddy||+10%||Very poor quality; bad worksmanship, cheap materials and outdated technology. 1-15% chance of device being this quality.|
|Poor||+5%||Poor quality; bad workmanship, cheap materials or outdated tech. 16-40% chance of device being of this quality.|
|Average||0||Average quality. 41-75% of device being of this quality.|
|Good||-10%||Good quality. High quality materials used. 76-90% of device being of this quality.|
|Excellent||-20%||Very good quality. Excellent materials, workmanship or innovative tech. 91-98% chance of device being of this quality.|
|Peerless||-40%||Exceptional quality. Excellent materials, workmanship and innovative tech. 99-00% chance of device being of this quality.|
I also added a set of higher quality thieves picks and tools to the equipment list. The "Peerless thieves picks and tools" cost 250gp, but grant a 10% bonus to all OL/RT checks made by the thief using them.
In addition, I came up with a system allowing for multiple attempts at picking a single lock. By the book, if the thief fails the first attempt, he must wait until he gains another experience level before attempting it again. This is a little unreasonable, in my opinion.
I rule that the first attempt at picking a lock takes 1d4 minutes. Each subsequent attempt is made at a -10% (cumulative) chance of success, and takes an additional 1d6 minutes (so, the first attempt is 1d4 minutes, the second is 1d4+1d6 minutes, the third is 1d4+2d6 minutes, etc)