Older iterations of RPGs seem to have more focus on exploring over combat (in early D&D you got XP from treasure, not killing things, so combat was less the assumed default). And older print games often had to de-emphasise other bits of the game given the real-world restriction on page count. That might make them look rules light in comparison to modern games but it may just be ‘rules different’.
In early D&D you MOSTLY got XP for treasure but also did get XP for killing things.
In 1974 OD&D monsters gave 100xp per HD (with adjustments up or down based on relative level of the character and monster), but Gary rapidly decided that was too generous and adjusted it way down starting in Supplement I: Greyhawk in 1975, and monsters continued to be the secondary xp source (roughly 20%, maybe, depending on the version) through every version until 2nd ed in 1989, which made treasure for XP an optional rule and set a guideline of 50% of available XP being from monsters and 50% from quest goals/objectives.
I have a slightly unorthodox take... I think the lower chances of success with thief skills is best married with a slight reinterpretation of what those thief skills MEAN.
OSE and Dolmenwood carry on mostly the traditional interpretations – you declare "I'm sneaking up on them" and then you roll Move Silently, you declare "I'm searching for traps" and then roll, etc – with the exception that OSE redefines Climb Walls to Climb Sheer Surfaces.
It seems like a subtle change, but Sheer is beyond the realm of most other folks' ability. It's not just a "generic climb skill." It's "holy crap they did an unassisted ascent of a 5.13 climbing route without handholds and a nasty overhanging ledge!"
"
Climb nearly sheer surfaces" was the original wording in 1975 Greyhawk when the class and skill were introduced.
Well, there was also a version before that, in
The Great Plains Games Players newsletter article "The Thief Addition", in 1974, where it was called "
Climb almost sheer surfaces rapidly, up or down".
1977 Holmes basic calls it "
climb sheer surfaces".
In the 1978 AD&D Players Handbook we first see it called "
Climb Walls", and it's notably the exception. AD&D 1E notoriously bones the Thief at every turn, through (aside from giving them a d6 HD), so this is par for the course.
1981 Basic goes back to calling it "
climb sheer surfaces" in the table on page B8 but "
climb steep surfaces" in the class description on B10. Expert goes with "
climb sheer surfaces" in the table on X6, so overall I'd say that OSE is being consistent with the predominant wording in B/X.
The more you make the thief skills EXTRAORDINARY, the more the higher chance of initial failure makes sense, imo.
For example, Hide in Shadows is typically – you declare, if you succeed and stay motionless, you ambush an enemy walking along. INSTEAD, I like to run it as: Hide in Shadows is an extra chance for the thief to avoid being detected even if their party does not have Surprise, thus allowing them to gain surprise (just them). It's like a reaction/shröedinger effect, where "ok, an encounter is happening, no one is surprised...buuut WAIT! was the thief lurking in the shadows all along and gets the drop on the monsters?"
This kind of interpretation goes back at least to Jason "Philotomy Jurament" Cone's seminal
Philotomy's Musings on his now defunct website, going back to 2007. Big influence in the OSR.
As traditionally played, Find/Remove Traps is the thief player's last resort when creative thinking fails. Traditionally, the skill doesn't interact with the player figuring things out. It's your backup plan.
To build on my "how I reinterpret OSR thief skills" post above, Find/Remove Traps is best reserved as a reaction kind of mechanic that embraces it's a lucky/skillful passive sort of last resort to fall back on...or applying in specific circumstances where the danger is already upon you. OR it's best used to answer specific questions a thief player has about a trap (so more like "Analyze" than "Find/Disarm").
I think it's important to note also that the Thief's ability to Remove Traps was originally (in Greyhawk and in the original The Thief Addition article) specific to small device traps. "
Remove small trap devices (such as poisoned needles)" is the GH wording. "
Removal of small trap devices (such as poisoned needles)" in the TTA article. Holmes Basic uses consistent wording as well, "remove small traps such as poisoned needles". Moldvay uses identical wording to Holmes.
The AD&D PH is more long winded, but again is talking about small mechanical devices.
"Finding/removing traps pertains to relatively small mechanical devices such as poisoned needles, spring blades, and the like. Finding is accomplished by inspection, and they are nullified by mechanical removal or by being rendered harmless."
There is no "find traps" Thief ability prior to 1978, just "remove". The 1974 set vol 1 notes that Dwarves "
note slanting passages, traps, shifting walls and new construction in underground settings", and gives some general guidelines for searching for things in Vol 3 but while that bit gives chances for finding secret doors and for listening for noises on a d6 roll, no such mechanics are described for finding traps (only a random chance of springing them if you blunder across them). With this void, the implication is that traps are either undetectable or (more likely) that you spot them by describing narratively how you search.
Holmes retains the Dwarves finding stuff language but adds a mechanic to the end
"about one-third the time", giving them a 1-2 on a d6 matching their chance to hear noises.
AD&D in the 1978 PH first introduces the concept of FINDING traps being part of the Thief's skills. IMO that was a mistake, and a real design error, multiplying the already low odds by implying that Thieves be forced to make two long-odds rolls instead of just one.
Interestingly the class description in Moldvay basic exactly matches the Holmes wording and omits "find", though the Thieves' Abilities table on B8 sadly titles the column "
Find or Remove Traps". The skill description on the same page reads
"Find or Remove Traps is a double ability. The thief has the listed chance of finding a trap (if there is one) and the same chance (if the trap is found) of removing it. Either attempt may only be tried once per trap."
Again, IMO, retaining and enshrining this tiny percentage to "find" traps was one of Moldvay's rare editorial slip-ups.
Moldvay does distinguish between the small mechanical traps Thieves find and disarm (referred to broadly as "Treasure Traps" on B52) and larger "Room Traps" (B52 again), such as pit traps, which anyone can search for and find on a 1 in 6 (B22), or Dwarves 2 in 6 (B22 and B9).
Overall I think the textual evidence supports a premise that the Remove Traps ability was always meant to apply only to small mechanisms which the DM and players are less likely to be able to handle with narrative description, not necessarily being familiar with the details of how such mechanical devices would operate. Larger traps like pit traps and crossbows and so forth, "Room Traps" as Moldvay labeled them, it seems were left out of the scope of the Thief ability. Which implies that they are either intended to be uncounterable (unlikely) or dealt with narratively, through any player describing to the DM what their character does in-fiction to counter it.
Dolmenwood (a refinement of OSE, which is a distillation of B/X) has an interesting approach where Gavin Norman uses greater specificity to limit the scope of Disarm Mechanism as well as clarify the risk involved.
It's not a perfect solution, but what it does is to divide traps into two sorts: (A) the clockwork type bypassable by the thief with a roll, and (B) everything else that you've got to use your 'noggin to figure out.
Yes, this is a smart approach to Thief adjudication and it's something the written texts for every version of 1970s and 1980s D&D and AD&D are conspicuously and sadly missing, though it's sort of implied.
Expert Set (Cook & Marsh) also has an Optional rule on page X51, which stipulates the DM can ask for a 'roll under' saving throw versus any ability. This introduced minigames for any class. We used that rule often when 'Player Skill' failed and the group was stuck.
During the early 80s, Saves vs Ability (X51), Variable weapon damage (B27) and Individual Initiative (B23-24) optional rules were very popular in my area.
As a quick note, with the ability saves Marsh and Cook were reiterating something Moldvay included in 1981 Basic on B60, under the "There's always a chance" heading in the Dungeon Mastering as a Fine Art section of advice.
As far as I've been able to determine this is the first time in any core D&D book that the concept of rolling under an ability score as a generalized mechanic was introduced. There are at least one or two instances of it appearing as a bespoke mechanic for a specific spell, though, like in the Dig spell in the AD&D PH in 1978.
