A level 5 rogue will quite probably have a thievery dc of 13, if they invest in it and max dex. The average lock has a dc of 25 and requires 4 successes. It takes a roll of 12 or better to have a single success, and will average about 9 rolls to rack up those 4 successes. With 9 rolls wherein you crit fail on a 2 or lower, the likelihood of breaking a pick is ~61%.
Should a level 5 rogue take a minute to open the average lock, and more likely than not break a pick in the process?
And let’s look at a good Lock: DC 30, requiring 5 successes. The level 5 rogue will only succeed on a 17, meaning it will take on average 20 attempts to get those 5 successes. On one attempt in a thousand our Lvl 5 rogue will open this lock before breaking a pick, and will typically break 3 in the process.
Am I missing something?
It’s a pretty realistic expectation for a mediocre locksmith in the real world faced with the average door lock. It’s a bit slow for the fantasy expert lock picking thief who’s invested their ability and skill increases to excel at a mundane and achievable task. But time spent is the smaller issue.
And it’s 3 gp a thieves tool set, but the bigger issue is bulk. God forbid you’ve a dozen doors with good locks in a dungeon, that’s 4 bulk worth of picks to get through–pretty much the thief’s whole inventory–and a 50 percent chance of ultimate failure (not to mention 240d20). Pretty rough on the class fantasy. If nothing else I’d change the names of the locks to pad the thief ego: poor becomes average, average good, good master and master legendary. I don’t want my player stymied by an average door because he only brought one backup toolkit.