Awhile back I meddled with the old school (read: AD&D) thief class, changing the checks to a 2D6 mechanic. It also involved revisiting how the thief skills work, placing them within a more coherent skill system approach.
Here is that work:
A Look at the Thief Class
By pladohs_ghost
As part of reworking the Thief class for a system I’m working on, I’ve taken a hard look at the thief abilities. Tweaking the thief has long been common in D&D circles, so I’m going to offer up my take on the class for anybody interested to use. I’m staying close to the RAW for 1e AD&D in this text, while adding in elements I think add to play.
The first issue I’ve had for ages is this: I find some of the chances listed for skills to begin far too low to be truly useful—and also so low as to disturb my sense of simulation. I don’t think any thief would be viable at low levels because they wouldn’t be competent enough to stay out of trouble with the authorities long enough to develop competence, even if the GM awards a bonus for easier locks or traps or whatever. So, the chances for success need to be tweaked to keep me happy.
The next issue involves taking a look at how the thief’s capabilities compare to those of non-thieves. Thieves aren’t the only characters who can climb and sneak and such—they’re just better at it. I think specialists in skills should be qualitatively better than non-specialists, in addition to quantitatively better. A close look at Gygax’s commentary on thief skills in the 1st edition DMG helps. He lays out some detail on judging thief skill use, so I’m using that as a guide as I play with things.
I’m also keeping in mind that the early editions do all have skills systems, though not formally laid out as such. All of the X-in-6 chance activities are skills. (Lucy Blumire pointed this out years ago, here: https://llblumire.co.uk/blog/2020/07/11/skills ) Skills in the early systems thus reach beyond the thief’s explicit skills.
I find the X-in-6 chance ratings far too crude to work well for me, in terms of development. I want greater granularity. I’ve approached this before with the thought of using a D12, as that doubles the granularity and keeps the change in percentages in even chunks. I’m bothered by that a bit because it adds yet another type of dice roll just for one subsystem, a bit inelegant. I’d rather use a roll that’s used elsewhere in the rules. I’m using 2D6 rolls for the skills, same as with reaction checks and the like (using 2D6 for everything except attack rolls and saves, at this point).
A note about using a 2D6 roll mechanic: a TN of 10+ is the same as a 1-in-6 chance. The 2D6 roll chances deviate from 1D6 chances aside from that. It’s useful, though, to have that particular correspondence, as there are many 1-in-6 chance skills in the systems.
What follows is my take on the Thief. There are three parts to it. The first is a description of the class as it appears in the PH and noting the changes in the resolution system (and corresponding chances). The second part explains the thief abilities and adds rules for non-thieves using them (where applicable). I treat thief abilities as mostly mundane in nature, instead of viewing them as mostly mystical abilities. The beginning ratings offer better chances, in general, while the ratings at high levels are pulled back a bit (No “zero to superhero” development; “competent to famous expert” is what I’m aiming for). The third part offer up tables of bonuses due to attribute ratings and bonuses due demi-human thieves.
Part One: The class description
The Thief
A thief may specialize in raiding tombs or burglarizing homes of the wealthy or simple snatch-and-grab or picking pockets. One may eschew stealing from poorer citizens and focus efforts on separating the rich from their excess. Or, one may simply steal where the opportunity presents itself. However a thief chooses to use their abilities, the prospect of some loot from a forgotten tomb or ruined estate or deserted city will certainly pique interest, and their abilities will be welcomed by others involved in the endeavor.
Primary Attribute
Thieves rely on physical coordination and precision to perform their duties. Thus, a modicum of talent in that area is required. Extraordinary talent garners a bonus on experience points awarded in play and also a bonus when using thieving abilities.
Minimum Dexterity Rating: 10
Experience Point Bonus: +10% at 15+
Bonus to Thieving checks: covered later
Basic Fighting Ability
Thieves are masters of cunning and stealth, gathering loot by stealth. As such, thieves aren’t great fighters, being neither highly durable nor exceptionally handy with a blade. An experienced thief, however, can overpower unremarkable (read: 0-lvl) persons with relative ease.
Hit Die Size: D6
To Hit Advancement: +1 per three experience levels
Thieving Abilities
The primary functions of a thief are: (descriptions below)
Picking Pockets
Opening Locks
Finding and Removing small traps
Sneaking
Hiding in Shadows
The secondary functions of a thief are:
Listening at Doors
Climbing Vertical Surfaces
Back Stabbing
Additional functions of a thief are:
Thieves’ Cant
Read Other Languages (upon reaching 4th level)
Decipher Magical Writings & Use Scrolls (upon reaching Master Thief level)
A Thief’s Stronghold
Thieves cannot build a stronghold upon reaching name level (Master Thief). They can build fortified buildings or small castles/manor houses, as long as it is built in, or near, a town or city.
The Master Thief may then use the stronghold as the headquarters for a gang or guild of thieves. The new organization will draw attention from a rival guild of thieves, which will attempt to eliminate the PC’s group. The fighting will only end when all Master Thieves on one side are dead, or the thief PC moves the new operation away.
Followers gained: 4 – 24 thieves of varied levels
Thief Function Bonuses
When using their PCs’ thieving functions, players roll 2D6 for the checks.
Check Roll: 2D6 +bonus vs TN 10 (see below)
Backstab Damage multiplier begins at 2x and advances by another multiple every four experience levels.
Climb Vertical Surfaces begins with a bonus of +5 and advances by +1 every six experience levels.
The Primary Functions listed above begin with a bonus of +2 and advance by +1 every two experience levels.
The Listening at Doors ability begins with a bonus of +1 and advances by +1 every five experience levels.
The Read Other Languages ability begins at 4th level at +0 and advances by +1 every three experience levels.
The ability to Decipher Magical Writings & Use Scrolls becomes available at 10th level with a bonus of +4. The bonus does not increase with experience level.
Part Two: Notes Regarding Thief Functions
As mentioned prior, my approach to thieves involves a close look at the abilities and how to adjudicate them. This examination includes the capabilities of non-thieves attempting the same abilities and how the thief has a qualitative and quantitative advantage in comparison.
This examination of the abilities relies heavily on Gygax’s commentary in the 1e DMG, in conjunction with the descriptions he provides in the PH. Even referencing both of the texts doesn’t always provide clarity on an issue, so I’ve simply made a decision that matches my taste in those situations.
The examination of the abilities appears in a different order here than in the PH. I begin with the two abilities Gygax reports as the most abused in play: Climbing Walls, and Hiding in Shadows. Those two examinations highlight the approach taken herein, with contrasts between thief capabilities and non-thieves attempting same.
Climbing Walls
The Players Handbook description simply offers that a check is required at the halfway point of any climb, with failure indicating a slip and fall. The DMG discussion clarifies that a check is required for each round of climbing, so those tall castle walls are more of a challenge than the PH description would imply. The checks are required for both vertical and horizontal movement.
The movement rate while climbing on walls varies by the type of surface and by the condition of the surface. A rough surface with plentiful handholds is easier than one with barely a crack to be seen, and a dry surface is easier than one covered with moisture or slime and thus quite slippery. He offers a table of movement rates based on these criteria, which can add a great deal of verisimilitude and tension in play.
General Parameters
As part of being qualitatively better at climbing, thieves can climb surfaces that others can’t. Thieves can climb vertical surfaces, fairly smooth surfaces with few obvious handholds, and even some inversely-inclined surfaces. When climbing non-sheer surfaces, thieves need not make climbing checks, though they may be slowed by the conditions of the surface.
Non-thieves can climb surfaces that, while difficult to ascend, aren’t so challenging to require the specialized training of a thief. Surfaces that are not vertical and smooth, meaning those that have an incline of no more than 80% and are rough enough to provide obvious handholds for those attempting the climb. Non-thieves climb at a rate half that of thieves on the same surface.
Climbing Checks & Saves
What I would add to the mix is fairly straightforward and relies on the success or failure of a climbing check. A failed check requires a Save vs Breath Weapon to adjudicate the effect, which can be a slide or a slip. This check is required for thieves climbing vertical surfaces and for non-thieves climbing nearly-vertical surfaces.
* A successful save indicates that the climber suffered a slide, only. The climber loses a round’s worth of movement after they catch themselves and regain a working grip on the surface.
* A failed save indicates a slip and fall. The climber loses their grip and can’t stop themself from falling. Normal falling damage accrues.
If the climber fails a second climbing check during that climb, the effect varies by whether the climber is a thief or non-thief.
* A thief may slide or slip, the same as above.
* A non-thief will automatically slip and fall on a second climbing check failure.
(Note: Thieves need not check for climbing on surfaces non-thieves can climb; thieves are automatically successful on those surfaces.)
If a thief fails a third climbing check during a single climb, the failure indicates a slip and fall—no saving throw allowed to mitigate it.
The movement rate while climbing varies by the surface. A climber may attempt to increase the movement rate—rushing the climb—which results in penalties to climbing checks. For each increase in movement category, a -1 penalty applies. Conversely, if a climber slows their pace, taking greater care, then a bonus of +1 applies to climbing checks (Note: this is a blanket bonus, not per category slowed).
Difficulties & Conditions
There are five difficulty ratings used to evaluate surfaces. The more difficult the surface, the slower the base movement rate on it while climbing. The condition of the surface may slow movement further.
Surface Difficulty Base Move
Tricky: 24’ per round
Challenging: 18’ per round
Demanding: 12’ per round
Arduous: 9’ per round
Prohibitive: 6’ per round
Additional movement rates due to poor surface conditions.
3’ per round
1’ per round
Notes:
Tricky surfaces are those that non-thieves can climb.
1’ per round is the slowest movement rate.
Surface Condition Effect on Check Effect on Move Rate
Dry None None
Slightly Slippery: -2 penalty -6’ per round
Slippery: -4 penalty -12’ per round
Hiding In Shadows
The thief skill that vies for being most abused, according to Gygax, is that of hiding in shadows. In my experience, this is the most abused, as I’ve seen many a player try to hide while being observed, as if witnesses were to suddenly lose all memory of the PC’s location while watching the thief move about.
In RAW, a thief must make an unobserved attempt to hide, requiring a dice roll. The thief player doesn’t know how the roll turns out and won’t have any idea if the attempt is successful until play reveals that the thief was spotted or the thief goes unnoticed. While hiding in shadows, the thief must be silent and motionless or they will give away their location.
Gygax makes it abundantly clear that hiding in shadows is never possible while the thief is under direct OR indirect observation. In melee, specifically, if a combatant’s vision would normally extend to the thief’s area of activity, the thief is under observation; dropping back from the party after encountering something is thus not possible, as the foes have seen the thief and the thief is under at least indirect observation as the foes are looking in that general direction. Again, if a thief moves while hiding, the jig is up if in any location under direct or indirect observation. A hiding thief is also subject to detection as if they were invisible.
I would add some modifiers to hiding attempts based on how deep the shadows are, whether there are objects in the shadow to aid in the attempt, and how far into the shadows the thief is.
Quality of Shadows Bonus or Penalty
deep shadow +2
regular shadow +0
light shadow -2
Objects in Shadows Bonus or Penalty
many objects +2
few objects +0
very few or none -2
Distance Into Shadow Bonus or Penalty
deep, more than 20’ +2
moderate, 10’ to 20’ +0
shallow, 5’ to 10’ -3
Non-thieves may attempt to hide in shadows with a penalty of -3. They must check every other round to stay hidden; these additional checks at a reduced penalty of -1.
Moving Silently
The ability to move silently has often been used as a backup check to a surprise check. While I think that’s a workable approach, I’d rather use just a single roll for each PC, so working the move silently skill into general use as a surprise check is a more efficient approach. Gygax reports the default movement rate for moving silently is the same as exploratory movement, so it works well to merge the surprise check and move silently check into one roll.
The RAW call for a surprise check when chancing upon others—NPCs or creatures—while moving along or when attempting to sneak up on a victim. We can see two use cases therein. The first case involves moving normally and chancing upon others without any intent to sneak; this case involves each party involved in the encounter checking for surprise. The second involves an actual attempt to sneak up on somebody or something, with the party doing the sneaking not having a chance to be surprised—only the party being snuck up on.
There are limitations presented as to how the chance to surprise others can be limited. Light sources can give away presence in dark environs, negating any chance to surprise others, for example. Noise can likewise give away presence, as can odor. Anything that can be sensed by the other party can give away the presence of the PCs.
The distance at which one of the parties becomes aware of the other (or both aware simultaneously) is variable, determined by the roll of dice. It’s entirely possible to be surprised by, or surprise others, at a distance where neither side can take advantage of the other. (I can recall such an annoyance happening far too frequently at my table, until I learned to check encounter distances before bothering to roll for surprise.) Note that this approach changes surprise rolls from checking to see if the PCs are surprised, to them rolling to see if they surprised the others, changing the feel of the check a bit.
I would expand the use of surprise rolls as sneak rolls expressly to sneak past somebody, too. Sneaking past guards is a common enough activity and making it explicitly a use for a sneak/surprise roll seems obvious. Witnessing GMs call for percentile checks or saving throws at other tables, though, tell me it’s not an obvious use for some.
As the 10+ TN is a 1-in-6 chance and most critters and beings are surprised at a rate of 2-in-6 in RAW, I figure every PC has a base +1 in sneak. This raises the chance not quite to 2-in-6, yet more than 1-in-4, which I find a reasonable rate. This bonus applies to all uses of the sneak roll: group surprise, individual surprise, and sneaking to remain undetected in moving.
Thieves, of course, have larger bonuses to sneaking. A group of thieves moving together will surprise others according to the worst sneak bonus among them; only the player of that PC need roll for the check. Again, thieves have better chances to sneak up on and surprise a target or sneak by a target.
I’ll add in three elements that can affect the chances of sneaking successfully: the distance between the parties, the rate at which they’re moving, and how much noise is present.
The distance at which the check happens
greater than 30’ +2
15’ – 30’ +0
5’ – 15’ -2
The rate at which a party or person is moving
half normal speed (6’/rd) +2
normal speed (12’/rd). +0
half again normal speed (18’/rd) -2
faster than 18’/rd. -4
Background noise
general silence -2
regular background noise levels +0
noisy background +2
The distance modifiers only consider distances in dungeon environs, as listed. Distances for wilderness encounters are most likely going to be at least 30’, though in some circumstances one may happen closer. In that situation, use the indoor/dungeon distance guidelines above.
Back Stabbing
Thieves are notorious for stabbing targets in the back, though that notoriety may be better laid at the feet of assassins. A perfect backstab can leave even high-level targets dead from a single attack.
RAW require a backstab attack to involve attacking from behind a target while wielding a club, dagger, or sword. The attacking thief must surprise the target, first, and then attack with a bonus of +4 to hit. If the strike is successful, then damage is multiplied (2x to 5x).
The attack form relies on the thief being able to hide and/or sneak up on an unsuspecting target, which is not always straightforward. Opponents aware of the thief’s presence—such is a melee where the thief has already been seen—will automatically negate the attack form. If a target knows the thief is around, no back stab opportunity. There are also creatures that have the ability to negate surprise and some that have no discernible back, so those can’t be struck using the back stab ability (though they can be attacked from behind, certainly).
I much prefer that back stab attacks have serious consequences if perfectly executed. This means that the thief surprises the target, gains a +4 bonus to hit, and then the damage involves a full die of damage for each multiplier; a 2x multiplier with a short sword, for example, adds a full die—6 points—to the roll of the first damage die, making for a strike that does 7 – 12 points of damage.
If the thief doesn’t surprise the target, I still want the attack form to be consequential. The thief will attack with a bonus of +2 for being to the target’s rear. If successful, the strike does damage according to the multiplier, though each die has to be rolled, e.g., a 2x multiplier with a short sword delivers 2D6 damage, or 2 – 12 points. An imperfect back stab can thus be as effective as a perfect back stab, though it’s unlikely.
A non-thief attacking with surprise from behind gains the +4 bonus to hit and, if successful, the strike will inflict maximum damage for the weapon (e.g., 6 points of damage with a short sword).
Picking Pockets
Picking pockets is something that doesn’t seem to arise often in many games, which is a shame. Purloining a letter or signet or the like from an NPC is something that adds to an adventure, providing some tension without bloodshed. If the thief happens to snag a piece of jewelry at the same time, then the situation is even better.
RAW call for a check for each attempt, with a couple of attempts possible each round (fiction permitting, I reckon). If the attempt fails with a roll close to success, the victim doesn’t notice the attempt. If the check fails with a roll significantly different than the TN, the victim notices—though may not immediately react. A successful check garners a random item unless the thief knows the exact location of a desired bit.
The primary limitation on picking pockets is that the level of the NPC mark affects the check. Attempting to pick a high level character’s pocket unwittingly can prove dangerous to a PC thief.
I’ll suggest, first, that non-thieves can attempt to pick pockets, too. They operate with a penalty of -2 and never improve over time. This effectively means they have a slight chance to succeed, and that only in favorable situations. Still, if they wish, filching an item here or there from typical citizens is possible.
Thieves begin with a bonus of +2, as this is a primary function. The chances are limited by the level of the mark, and how sober the mark is. An additional threat of a witness noticing the attempt and giving alarm is also factored i; if the check fails by the crowd penalty or less, then a witness notices.
Level of the Mark Bonus/Penalty
0 – 1 +0
2 – 4 -1
5 – 7 -2
8 – 10 -3
11+ -4
Condition of Mark Bonus/Penalty
diligent -2
generally sober +0
obviously drunk +2
Chance of Witness Bonus/Penalty
no crowd +2
small crowd +0
large crowd -2
Opening Locks
In the RAW, the thief has an ability to open locks, which includes sliding puzzle locks and magical closures. Opening a lock can take 1 – 10 rounds, though most are simple enough to require only 1 – 4 rounds to open. Opening locks requires a set of tools and cleverness. Thieves are assumed to study and practice on locks regularly.
If a check is successful to open a lock, then that lock is now opened. If the check results in failure, the thief may not attempt to open that particular lock until having achieved another experience level.
I’d add a bit to this whole process. The complexity of the lock should affect the time required for an attempt to open it. Some locks are more difficult to open than others. A good toolset can make all the difference in succeeding. Failing to open a lock may damage the lock or a tool, so there may be consequences to failure beyond not opening the lock.
Lock Complexity Time Required for Attempt
simple lock: 2-5 rounds
moderate lock: 2-8 rounds
complex lock: 2-12 rounds
Lock Difficulty Bonus or Penalty on Check
easy lock: +2
moderate lock: +0
difficult lock: -2
Toolset Used Bonus or Penalty to Check
excellent tools: +2
regular tools: +0
poor tools: -2
Chance of Breakage
failure by <5 none
failure by 5+ break
If a break is indicated, roll 1D6.
On 1-3, a tool breaks.
On a 4-6, the lock breaks.
A broken lock cannot be picked open thereafter.
A non-thief can only pick the simplest and easiest of locks, even when using the best tools. The chance of breakage increases when an attempt fails, with failure by 3+ indicating breakage. Non-thieves have a penalty of -2 on all attempts.
Finding & Removing Traps
While attempting to open locked doors or chests, a thief may want to check for traps on or around the mechanism. A thief can detect small mechanical devices such as poisoned needles, spring blades, and similar mechanisms. Such traps may be thwarted via removal or rendering the mechanism inoperable. This ability is limited to small traps, such as on chests or door locks and similar
Find traps and removing traps are separate tasks. They are checked for the same as for opening locks, above. A thief has but one attempt to find a trap; they may try again after gaining a level of experience.
I think there should be adjustments to finding traps based on how well a trap is concealed. When removing traps, how accessible the mechanism is should be a consideration. In addition, sometimes disabling a trap is but a temporary measure and the trap will return to working condition after some time.
Concealment Bonus or Penalty to Check
poorly concealed +2
normal concealment +0
well hidden -2
Accessibility of Mechanism Bonus or Penalty to Check
easily accessible +2
moderately accessible +0
barely accessible -2
Check Success Margin Lenth of Time Disabled
success by <=1 1-4 turns
success by 2+ permanent
Trap Complexity Time Required for Removal
simple trap 2-5 rounds
moderate trap 2-8 rounds
complex trap 2-12 rounds
Non-thieves have a penalty of -2 on all attempts.
Hearing Noise
This is a task that Gygax makes clear can be done by non-thieves, with a process outlined for general hearing attempts laid out elsewhere in the DMG. That discussion of listening at doors lays out base percentages based on character race. Gygax also includes the possibility of a PC being keen-eared, gaining a permanent bonus to checks if the PC is successful at the task the first time in attempting it.
A PC must remove all headgear to listen at a door, which requires time to remove and put back on; if the party is attacked during that time, the PC must fight sans helmet, which places them at great risk of a blow to the head. Each character listening requires some 2 1/2 feet of space, meaning even the standard dungeon door can only accommodate three listeners at one time.
Each attempt lasts a round. Only three consecutive rounds may be spent listening before strain sets in, which requires five rounds of rest before attempting to listen again. During the listening attempt, all members of the party must be as silent as possible.
I’ll suggest making the door, itself, affect the chances of hearing anything on the other side. The thickness of the door should make a difference (I’m only considering wood doors, at this point). In keeping with the expertise of the thief, a thief will not suffer any mistaken impression results, whereas non-thieves can make such a mistake.
Door Thickness Bonus or Penalty
light door +2
normal door +0
extra-stout door -2
Result by Class Outcome
All, success impressions of what might cause sound heard
if there are sounds to be heard
Thief, failure no sounds noticed
Non-thief, failure
by 3 or less no sounds noticed
by more than 3 mistaken impression of sound
A mistaken impression can take the form of hearing sound when there is none to be heard, or to hear a sound and ascribe it to something totally different than what it is—believing a sound is voices instead of wind whistling through an opening—or to not hear any sound despite there being activity behind the door.
Non-thieves have a bonus of +0, modified by any bonus or penalty due their race (see below).
Reading Languages
Upon gaining a fourth level of experience, a thief can read bits and pieces of languages they aren’t able to speak, at least to the extent to read some instructions and descriptions on treasure maps and the like. They may attempt to read inscriptions and writings once at their current experience level; further attempts can be made at higher levels.
A successful check means that the thief can understand a portion of what’s written. The rate of comprehension begins at 20% and increases to 80%, the increase mirroring that of the chances of the thief to read the language. On a failed check, the thief comprehends none of the script. The thief does not have the ability to read ancient or strange languages, as determined by the GM, because the ability is predicated on having encountered the language prior.
I see this ability as providing a chance to pick up on key concepts in a passage of writing; common words will be far more recognizable than rarely used words.Whereas a non-thief might be able to identify what language some script around a stone portal is written in, a thief may be able to decipher enough to learn that a great evil is locked inside, or a specific phrase warning of danger to those attempting to open it without a key, or so on.
The chances of reading bits and pieces also should depend on how closely the language matches one the thief can already speak. The script system used should also affect comprehension, with some writings more difficult to parse.
Language Difficulty Bonus or Penalty
closely related to known language +2
related to known language +0
distantly related to known language -2
Writing System Bonus or Penalty
alphabetic/syllabic +0
hieroglyphic/ pictographic -1
Deciphering Magical Scrolls
Thieves gain the ability to read magical scrolls at 10th level, casting the spells thereon. Clerical scrolls are excepted from this, though druidic scrolls can be used. There’s a 25% chance of misreading the scroll, though, and increasing chances of mispronunciations that can lead to a spell reversal.
I think this is a solid basic approach. I’ll break it out into two checks for a successful casting from the scroll, though—a (mis)reading check and a (mis)casting check. The casting check is only needed if the thief passes the reading check, of course. The difficulties increase as the level of the spell on the scroll increases. I also want miscasts to have varied effects.
Misreading a scroll spell means nothing happens. The spell is still on the scroll and may be attempted again after the thief has gained another experience level.
Spell Level Bonus or Penalty to Read
1st or 2nd +0
3rd or 4th -1
5th or 6th -2
7th or 8th -3
9th -4
Miscasting a spell should prove dangerous to the thief, leading to a bit of hesitation before attempting such a thing. With the power comes danger. The odds of miscasting also increase by spell level. A check is made for casting only if the reading check is successful.
Spell Level Bonus or Penalty to Cast
1st +0
2nd or 3rd -1
4th or 5th -2
6th -3
7th -4
8th -5
9th -6
Miscasting Fail Margin Effect of Miscasting
fail by 1 or 2 reversed spell
fail by 3 or 4 magical burn to thief
(2D4 +1D4 per spell lvl)
fail by 5+ Area of Effect magical burn
(5’ radius per spell lvl)
(2D4 +1D4 per spell lvl)
A thief casting from a scroll takes twice as long as a spellcaster using the scroll.
Part Three: Bonuses Due
Bonuses Due to Attribute Score
The bonuses due extraordinary attribute scores used in AD&D are intended for use with a D20 roll mechanic. Those bonuses don’t transfer well to use with a 2D6 roll mechanic; a +4 bonus is much stronger with a 2D6 mechanic. On a D20 roll, +4 is a 20% improvement; with a TN of 10, +4 on a 2D6 roll is a 55% improvement. Because of this, bonuses due attribute ratings have to be altered.
Ratings of 15 – 16 +1
Ratings of 17 – 18 +2
Strength Bonus applies to: (Normal STR bonus applies to Back Stabbing To-Hit rolls)
Climbing Walls
Dexterity Bonus applies to:
Picking Pockets, Opening Locks, Removing Traps
Intelligence Bonus applies to:
Deciphering Magical Scrolls, Reading Languages
Wisdom Bonus applies to:
Hearing Noise
Bonuses Due Non-Human PCs
The bonuses and penalties listed in the PH are in increments of 5%, which is perfect for conversion to D20 rolls from percentile rolls. They don’t work so well for conversion to 2D6 rolls, as even a +1 vs TN 10 is an 11% increase in chance of success. Because of this, I’ve removed most of the bonuses and penalties for demi-humans; I figure each of the non-human peoples can generally garner a +1 bonus and a -1 penalty to reflect differences among them.
Dwarf: +1 Finding/Removing Traps
-1 Climbing Walls
-1 Listening at Doors
Elf: +1 Hiding In Shadows
-1 Opening Locks
Gnome: +1 Moving Silently
-1 Climbing Walls
+1 Listening at Doors
Half-Elf: —- -1 Listening at Doors
Halfling: +1 Hiding In Shadows
-1 Climbing Walls
Half-Orc: +1 Climbing Walls
-1 Reading Languages
-1 Deciphering Magical Scrolls
Human —- -1 Listening at Doors