This is one of those little D&D things that make me twitch from time to time. So far it has never actually come up in a game I've run or played in, but if I dwell on it for very long, I can't think of a good reason that it shouldn't, except that it may have repercussions that aren't all fun, so you just metagame the situation and ignore it so things are fun.
Anyway, the clever rogue picking a lock or bypassing a trap to get to the loot is a D&D staple, especially at the lower levels of the game before the characters can smash or blast their way past most mundane obstacles. My problem with it is this: strictly by the rules, the locks and traps are often worth as much or more than the treasure they guard.
For example:
A goblin adept keeps a few herbs, mushrooms, ceremonial vestments, and a ceremonial dagger in a small chest. She has an average quality padlock on the chest to discourage the rowdier goblins from getting at the 'shrooms before temple services properly begin. Then some first level adventurers show up, clean out the goblins, and start looting.
The rogue gets to the adept's stuff and either picks the lock or does a thorough search and finds where she hid the key. Nobody back in town wants Maglubiyet vestments, and the 'shrooms probably need a bit of refining before they are worthwhile to take to the seedier side of town, and there may be alignment issues with such an endeavor anyway. So unless the rogue has Craft (narcotic) and/or modestly evil tendencies he takes care to hide from the paladin, they probably get left also. That leaves the ceremonial dagger. A quick Appraise suggests it can probably fetch about 75gp from a jeweler or curiosity shop. Not bad for first level.
The vanquished goblin king also kept a locked chest, his equipped with a deadly (well, at least inconvenient) CR 1 poison needle trap. Inside is the majority of the goblins' wealth: a small bag of gold, two bags of silver, a few scattered platinum pieces and small gemstones, a gold chalice or nonmagical ring or necklace, and perhaps a potion of cure moderate wounds. Total value: about 1,000 gp. Combined with the goblin king's +1 magic sword, the masterwork chain shirt off the guard captain, plus a few other valuables here and there, it's been a decent haul for our mighty first level heroes.
They head back to town, leaving the lock and trapped chest behind. But wait a minute. An average lock is worth 40 gp (effectively 1/3 of the adept's treasure) and the poison needle trap in that chest is worth a hefty 1,300 gp according to the DMG, worth more in fact than the treasure it did so little to protect. Presumably the lock on this chest is also at least of average quality, most likely built into the chest. By leaving the two chests and locks behind, the adventurers have abandoned materials worth about 1,400 gp if purchased on a market, or probably about 20-25% of the goblin's wealth.
Why?
Why are locks and traps left behind by so many adventurers when some of them scrounge around for every last silver piece (and won't pass up the coppers if they're already bagged up)?
As a side note, what if a party stumbles onto that game-breaking combo of bolt cutters (Arms and Equipment Guide, 6 gp) and the Mending spell? Encounter an amazing padlock on a thick iron door? Rogue: "Somebody get my bolt cutters off the pack mule and have the cleric mend this thing so we can try to sell it to a locksmith back in town. He could probably make a key and still sell it for a profit. Mr. Barbarian, help with the cutters, please?"
Sure there are ways a DM could just try to hand-wave the issue away. The internal mechanism of the trap breaks when it activates, for example. Replies the rogue: "I know how to make traps. We'll take it anyway and I'll see if I can fix it up; otherwise I might know a guy that knows a guy...."
Granted, some of the market prices and the Craft skill mechanic don't hold up well to close scrutiny. But even with judicious DM tinkering with them, it still seems like there are a lot of valuable locks and traps laying around. I'm curious if the idea of taking the treasure chest as treasure has ever come up in somebody else's game, and if there are groups that make sure to recover the locks and traps they encounter. If so, how did such thorough scavenging work out in game?
