Thief dilemma: traps

Continuing the examination of thief class abilities (begun here), I come now to Find and Remove Traps, and find myself in a bit of a quandary.

In the first place, I really, really like the idea of player agency in finding traps.  (See here and here for a much more in-depth look at this concept.)  It's much more interesting and provides greater immersion for the players to use the DM's descriptions to find traps.  This can be initiated either from the DM's initial description of a new area, or by the players stating that their characters are examining specific features. Consider:

DM:  Just ahead, on the left side of the corridor a skeleton is slumped against the wall.
Thief:  I check for traps.
DM:  (rolling)  You don't find anything.

or

DM:  Just ahead, on the left side of the corridor a skeleton is slumped against the wall.
Thief:  Without getting too close, I look at the walls and ceiling in that section of the corridor.
DM:  You see a pattern of holes in the right wall, and a set of shallow gouges in the left wall that seem to match.  There's nothing unusual about the ceiling.
Thief:  I examine the floor, looking for a trip wire or pressure plate.
DM:  One of the floor blocks is very slightly elevated above the level of the rest of the floor.

In my opinion, the second scenario is far more fun and interesting.  The "problem," if it can be called such, is that it renders the thief's Find Traps and Remove Traps skills irrelevant (or at least less relevant,) because it relies entirely on player (and DM) skill.  It allows characters to determine, or at least strongly suspect, the existence of a trap, and suggests ways that it might be avoided or nullified.  It doesn't require a thief at all; indeed, a fighter, a magic-user, or even a normal zero-level human could do it. 

This certainly intrudes upon the role of the thief, insofar as neutralizing traps is concerned.  (Quite a few old schoolers have noted that the addition of the thief class itself to the original D&D game usurped the shared function of trap finding from all the other classes, so this could be seen as restoring the proper order of things.)  Even though I'm a fan of the thief class, I think it's more than a fair trade, modifying the traditional role of one class for the sake of a more interesting and immersive game experience, but it raises a few questions.  What good, then, are the Find and Remove Traps abilities?  Should they be dropped entirely, or is there still a unique niche for the thief as trap finder?  I can see a strong argument in favor of keeping and using them in certain circumstances.

Dealing with traps as in the second example above requires that the DM be able to visualize the trap (else how could he describe it?) and have a basic understanding of its component parts and how it works.  It requires also that some aspects of the trap are visible to the player characters and discernible as something potentially hazardous.  Those conditions lend themselves best to area traps - those that affect a room or a stretch of corridor, for example - as opposed to item traps, such as a poison needle in the latch of a chest. 

I, for one, am hard-pressed to describe just what the trigger for a poison needle or a gas trap protecting a treasure chest would look like.  Besides making it difficult to describe such a thing, that also makes me skeptical of the ability of a cautious but untrained person to notice it.  Unless someone is familiar with all the bits and bobs of locks, hasps, door knobs, and such, how is he going to notice something amiss?  Imagine that someone has sabotaged the engine of a car, but that you know next to nothing about auto repair.  Whatever gizmo the saboteur has implanted under the hood is going to be indistinguishable from all the proper components of the car's guts to you.  You might see it, but it will utterly fail to register in your mind as anything untoward, even if you're looking for something untoward.

You can probably assume that the designer of the trap has taken great pains to make the external trigger of the trap both as small and as indistinguishable from the rest of the item as possible.  A specialist, someone who knows what he's looking for, has a chance to see it for what it is, but anyone else won't.  It's probably also a safe bet that most of the trap mechanism is housed within the chest, out of sight and out of reach, thus making disarming it difficult and delicate work.  You need someone with both knowledge of trap design and a practiced, steady hand.  So, yes, there is still a role for the thief as a trap detection and removal specialist, and the Find and Remove Traps skills will still see some use.

I actually don't see a need to modify the implementation of the skills much, within this restricted sphere.  Traps are hard to spot, so the low percentage of a low-level thief makes sense.  A thief should be able to search for traps as many times as he likes, each attempt taking a turn of game time, with all the attendant hazards and inconveniences that entails.  He can be confident with his first examination, or he can double-check, triple-check, and quadruple-check his observations until he's confident enough that he's found anything that's there to find.  You can mess with the player's head by having a chest trapped multiple times, with each search potentially finding one trap.

Removing the trap is also tricky business.  Bypassing a trap or its trigger is frequently the most practical option when dealing with area traps.  Of course, it's possible to do so with an item trap, but that naturally means not opening the door or chest in question, and thus it may be much more desirable to disarm the trap.  Again, the low chances of success don't bother me, because this is a delicate matter with potentially dire consequences, not simply a matter of time like picking a lock.  I can think of two options for applying the Remove Traps skill.  It can be attempted once, with failure meaning that the thief just doesn't know how to disable the trap mechanism, but the trap is triggered only on a critical failure, like rolling 95 or higher.  Alternatively, it can be attempted repeatedly but failure by some margin, say 20 points, results in the trap being accidentally triggered.  Either of these options encourages players to think of clever ways to trigger the trap from a safe distance (and hopefully more than a little paranoia as to just what a safe distance is!) at least at low levels when the thief's skills are still a dodgy proposition.