Clerics Wear Ringmail: Thieving for Non-Thieves

What do you do - as the ref - when a player not playing a Thief wants to do something that, typically, only a Thief is allowed to do?

This is a problem with skill systems - and an expose on how, the more you add to a game in terms of mechanical character complexity, the more you take away from the agency and imagination of the players. On a recent episode (or... well, an episode, at least) of John and Hannah Large's Red Dice Diaries podcast, John speculated on the subject - and I called in with my own solution.

Or, at least, the solution I use: as always, I refuse to claim that I thought of it first!

But either way - before I forget about it, I wanted to write it down - to post it here - in case you, dear readers, were interested in that solution and in the impact it has, numerically, on the game as played.

Maybe it'll work for you, too!

Attempting a Thief Skill as a Non Thief

If a character of class other than Thief wishes to attempt an action which should fall under the purview of a percentile-based Thief skill, they may do so - rolling 1d% under their Dexterity ability score. Thus, a Fighter with a Dexterity of 15 would have a 15% chance to open a lock - assuming said Fighter is carrying lock-picking tools or can otherwise improvise under the approval of the referee.

A non-Thief character attempting to Hear Noise has a static 1-in-6 chance of success.

Modified Thief Profile

A Thief character attempting to use a percentile-based skill other than Climb Sheer Surfaces, to determine their own chance of success, sums the value appropriate to level from the Thieves' Abilities table with the character's Dexterity ability score. Thus, a Thief with a Dexterity of 15 would have a 30% chance to open the lock referenced above - or, finding the lock to be trapped, a 25% chance to remove the trap.

If a particular skill - other than Pick Pockets - would be driven above 99% by summing the table value with the character's Dexterity, treat it as 99%: such that there is always at least a 1% chance of failure.

When attempting to Climb Sheer Surfaces, a referee may opt to apply the Dexterity modifier to the chance of success - but the chance of Climb Sheer Surfaces being so favorable to begin with, even for low-level thieves, this modification may be considered optional.

Hear Noise (Optional)

When attempting to use the Hear Noise skill, a referee may opt to have the character apply their Wisdom modifier to the roll. So - for example - a Thief of 5th level with a Wisdom of 13 would have a 4-in-6 chance to succeed rather than 3-in-6; a Fighter of any level with the same Wisdom of 13 would have a 2-in-6 chance; or a Thief of 8th level with a Wisdom of 4 would also have only a 2-in-6 chance.

If a positive Wisdom modifier would take the chance of success above 5-in-6, instead allow a re-roll on a failed attempt, succeeding on the margin of success: ergo, a name-level Thief with a Wisdom of 18 would have a 5-in-6 chance to Hear Noise as a base, but on rolling a 6, would be allowed to roll again: still succeeding on 3-in-6.

If a negative Wisdom modifier would take the chance of success below 1-in-6, instead force a second roll on success with an inverted chance of failure: that inverted chance being 6 less the negative modifier. For example, a Fighter with a Wisdom of 5 would have a 1-in-6 chance to Hear Noise as a base, but on rolling that 1, would need to "confirm" that success on 4-in-6 due to the -2 Wisdom penalty.

But what effect does this have on the game?

Surprisingly little, actually.

First, to speak to non-Thief characters the average Dexterity score is going to fall between 9 and 12 - so, comparing that level to a first level proper Thief, the Thief's niche is still protected.

So, assuming a Dex of 10:

	Open Locks	Remove Traps	Pick Pockets	Move Silently	Climb Sheer Surfaces	Hide In Shadows
Non-Thief Character	10%	10%	10%	10%	10%	10%
Thief, 1st Level (RAW)	15%	10%	20%	20%	87%	10%
Delta	+5%	+/-0%	+10%	+10%	+77%	+/-0%

Even RAW (that is, when the houserule is applied to non-Thieves, but the Thief is not boosted with their own Dexterity) - this gives a non-Thief a chance to accomplish something: but the Thief class is not superannuated. The Thief is still a good investment to have - or, even, multiple Thieves: in case you come across something that disallows retries (e.g. Open Locks).

But how about Thieves, themselves?

A Thief character is likely to have a higher Dexterity than the average character. This isn't because we're doing point buy or anything FOE like that - but if you're choosing to play a Thief, it's frequently because you rolled a high Dexterity anyway, which compliments your XP gain: plus, with B/X, at least, you can reduce your non-prime requisite abilities to boost your prime requisite - contributing to the difference.

Thus, assuming a Dexterity of, say, 13 (the minimum to achieve a +1 modifier and the minimum required to benefit from a Prime Requisite XP bonus): we find ourselves with the following, examining a cross-section at various levels:

	1st Level			3rd Level			9th Level
Thief Skill	RAW	Ruled	Lvl Eqv	RAW	Ruled	Lvl Eqv	RAW	Ruled	Lvl Eqv
Open Locks	15%	28%	4th	25%	38%	5th	75%	88%	10th
Remove Traps	10%	23%	4th	20%	33%	5th	70%	83%	10th
Pick Pockets	20%	33%	4th	30%	43%	6th	75%	88%	10th
Move Silently	20%	33%	4th	30%	43%	6th	75%	88%	10th
Climb Sheer Surfaces	87%	88%	2nd	89%	90%	4th	95%	96%	10th
Hide In Shadows	10%	23%	4th	20%	33%	6th	65%	78%	10th

Above, we have the RAW version of the Thief skill, the new success chance based on the house-rule, and the equivalent Thief level, RAW, which has a comparable chance. Note - the levels aren't perfect - for example, with Open Lock - a 4th level Thief, RAW, has 30%: not 28%, which is indicated as equivalent in the chart for 1st level - but it's the closest in the ballpark: and a fair approximation. Regardless - the implications are interesting.

Unsurprisingly, Climb Sheer Surfaces represents, on average, a 1 experience level improvement. However, for each of the other skills, the benefit appears to diminish as the Thief gains experience. That is, early on, we see an improvement of success rate of 2 - if a particularly good Dexterity is rolled - potentially even 3 experience levels: then, in the mid-level range, the gap shrinks, reducing from a 2-3 level bonus to a 1-2 level bonus at best. Finally, as the character approaches name level - the improvement firmly sits in the 1 category: and, at a glance, by 11th level, the impact is effectively moot: a name level Thief with a 3 Dexterity or a 18 Dexterity won't have a noticeable difference in their chances to succeed at most (if not all) of their percentile skills.

Having not delved into the Hear Noise equivalencies - really, it's x-in-6: it should be an easy compare for anyone willing to eyeball it - I like this rule a lot. Less so as a mechanism to cope without a Thief and more so as a way to make the Thief more attractive. The rule helps out lower level characters, who need help the most, but then evens out at higher levels: slowly but surely making sure that the character's experience level - not the randomly generated number they were assigned by fate at char-gen - is paramount to the determination of their success: something that Gygax was very concerned about, regarding the relevance of character abilities compared to class abilities in their effectiveness in game.

So - looking for a way to boost low-level Thieves, but not wanting to break your game or change the style of play or impact the thematic experience? This rule might be for you!

Delve on, readers - and let me know how it rolls!