Tuesday, June 7, 2022

Roll-Under-Ability Skill Test Methods Graph

A while back I wrote a post about why I disliked the Ability Check mechanic recommended in Old School Essentials and analyzed various alternative methods. I wasted a lot of words on it. Here is a graph that shows you the differences between several methods and you can draw your own conclusions. As you view it, keep in mind that in most cases a first level character with a particular class skill (e.g. hear noise) will succeed 33% of the time (a 2-in-6 chance as indicated by the gray horizontal bar).

Click to embiggen

After playing around with skill rolls for a while at the table, my conclusion is that, because every method other than d100 under is consistently better (unless the stat is abysmal) than a 2-in-6 chance, a roll under ability check with a d20 should only be used for skills that "anyone could do" and which are not a defined class skill. And even then I would probably ask for a 1-in-6 chance roll or not even bother with the dice.

In any case, class skills that seem like anyone could try them, i.e. "hide in shadows," need to be read as potent rather than mundane skills. In other words, the hide in shadows ability allows a thief to disappear in a brightly lit warehouse (in the shadow of a crate perhaps) or even behind another, larger character in a hallway. Characters without this ability couldn't even attempt such subterfuge, and should only be able to hide in shadows when it's really obvious that anyone could do it, e.g. standing in a side alley at night. 

Wednesday, April 13, 2022

ZineQuest 3: Roughly One Year Later

I bought a bunch of zines during Zinequest 3 on Kickstarter. Let's see how they are doing one year later. Spoiler, ROI is 82%.


  • Crawler (Due Oct 21; last update Feb 22.)
  • The Void of Thrantar (Due Oct 21; last update March of last year, 21, reporting the death of a principle.)
  • Before Fire (Due Aug 21; last update March 22.)
  • Realms of Peril (Due Dec 21; last update March 22.)
  • Many Crypts of Lady Ingrade (Due Oct 21; lost original artist, last update March 22 reports artwork complete.)

RECEIVED (23 - including all three categories below)

  • Pamphlet of Pantheons (digital only)
  • Colostle
  • Harrowings #03: Muspelhell
  • Dodeca RPG
  • The Drain
  • Lowlife
  • Planar Compass Issue 2
  • Desert Moon of Karth
  • Dethroners
  • Bloodheist
  • Courier
  • The Vaults of Torment: Blood is Fuel

READ (but not reviewed, yet)

  • Fresh from the Forge
  • A Bug's Guide to the Shimmer (digital only)

READ & REVIEWED (or at least mentioned on my podcast)

  • Siege: Pocket Warfare 
  • In the Shadow of Tower Silveraxe
  • Kriegsmesser 
  • Microvania 
  • Menagerie of the Void 
  • Not a Place of Honor
  • The Lighthouse at the Edge of the Universe
  • Wizard Funk 3

Tuesday, March 8, 2022

Skill Roll Math for Old School D&D

TLDR: skill checks should be made only when absolutely necessary and should probably never utilize the roll-under-ability score method. Various alternatives are analyzed.


The following largely pertains to iterations of D&D from 1974 to 1981. That is, in the era when the game did not have a strong concept of skill rolls outside of predefined elements within a class or ability. My baseline for the research below is Old School Essentials, which should be aligned with 1981 Moldvay/Cook Basic and Expert D&D. The purpose here is show how various methods of rolling skill checks stack up against prescribed skill checks by class.

Skill Check Methods Presented in OSE

In particular, I want to start with the fact that OSE offers a number of various ways to do skill checks. In classes, there are both x-in-6 and percentile chances expressed. (I consider a Save, which is d20 based, as something other than a skill check.) On page 216 of the OSE Classic tome, Gavin suggests that when a situation comes up that is not already covered by the rules (e.g. skill rolls as defined by class) the GM can "require the player to make an ability check (see p104) or a saving throw (see p105) to determine what happens. Other times, the referee may judge the likelihood of the action succeeding (e.g. expressed as a percent- age or X-in-6 chance), tell the player the chances, and let them decide whether to take the risk or not." For the record, Gavin describes an ability check as rolling d20 ≤ the relevant ability stat, sometimes with a modifier of up to +/- 4 applied by the GM. In the OSE Advanced Player's Tome, the ability check is the only method given (p. 204) for this purpose, but the Referee's Tome echoes the above paragraph, providing multiple methods.

Skill Check House Rules Survey

On my podcast, Plundergrounds, I recently broached the topic of skill checks and had quite a few suggestions and/or "this is how I handle it" call-ins. Among the suggested methods (aside from those defined by OSE above), were:

  • Roll d100 ≤ ability
  • Roll 3d6 (or even 4d6 or 5d6) ≤ ability
  • Roll d6 literally modified by relevant ability ≥ 6
  • Roll a pool of d6s equal to modifier of relevant ability ≥ 6 (if 0 or less roll 2d6 and take the worst)
Several individuals said they just set x-in-6 chances. (Spoiler alert - that's a pretty good way of doing it.)

Baseline Skills

Surveying level 1 characters in OSE Classic, the following skill areas are defined. Where a chance reads 33.3%, it has been converted from a "2-in-6" designation in the text.
  • Open Doors 17-83% (x-in-6 based on STR)
  • Detect Construction (Dwarf) 33.3% 
  • Detect Room Traps (Dwarf) 33.3% 
  • Listen at Door (Dwarf, Elf, Halfling) 33.3% 
  • Detect Secret Door (Elf) 33.3% 
  • Hide in undergrowth (Halfling) 90% 
  • Hide in dungeon shadows (Halfling) 33.3% 
  • Climb Sheer Surfaces (L1 Thief) 87.0% 
  • Find/Remove Treasure Trap (L1 Thief) 10.0% 
  • Hear Noise (L1 Thief) 33.3% 
  • Hide in Shadows (L1 Thief) 10.0% 
  • Move Silently (L1 Thief) 20.0% 
  • Open Locks (L1 Thief) 15.0% 
  • Pick Pockets (L1 Thief) 20.0%
If you subtract the more specialized Thief skills (in red) from this line-up and acknowledge that the STR-based Open Doors is going to be 33.3% (2-in-6) for the majority of characters (characters with an average ability score), you see the trend that a special class skill usually is set to that baseline of 2-in-6. 

This is an important baseline, because on-the-fly skill checks called for by the GM probably shouldn't supersede these class-based abilities.

Method Math

The following graphs and methods are compared to see which ones are in line with the spirit of the baseline skills of OSE. 

Dataset 1: showing d20 and 100 rolls vs. ability score target numbers

The Ability Check (row 3)

OSE recommended d20 ability checks are a bad idea! In one sentence: an ability check against an ability score of 7 (low by any one's standards) is superior to a baseline 2-in-6 chance (35% vs. 33.3% respectively). 

Let that sink in a minute. A character with an ability score of 7, well below average, will be more likely to succeed at a skill check than if that same character had a prescribed 2-in-6 class ability printed on their character sheet. Think of how this applies to something like Hide in Shadows. Unless, as a GM, we are willing to say no one but a thief (or halfling) can hide in shadows, then calling for a non-thief/halfling character to roll a DEX check allows them to be better at that particular dodge than classes that are supposed to be very good at it. (Forget the argument that thief's get better at it over time; a thief has to get to 6th level before getting a better than 35% chance to hide in shadows. And we would presume that a thief's DEX is far better than a 7 in virtually every instance.) Across the board, this method makes ability scores matter more than class abilities, and generally speaking a character would be better off rolling d20 ≤ Ability than rolling a class skill. 

Note that an ability check vs. an ability score of 17 (85%) is better than a 5-in-6 chance. Compare that to the Open Doors 5-in-6 for a STR 18. In other words, an ability check vs. a 17 STR is superior to an Open Doors check using an 18 STR. 

Yeah ... d20 ability checks are flawed. Sadly they are intuitive and therefor attractive to many GMs.

3d6 (or more) ≤ Ability (rows 4-6, shaded)

This is a clever way of doing things. It creates a very different curve. Note however that where this roll becomes superior to the 2-in-6 baseline is still pretty low. At 3d6 an ability of 9 is better. At 4d6, a 12. At 5d6, a 16. (These are signaled by red text.) Therefore, even if you ratchet up the difficulty with more dice, someone with a reasonably high ability will beat out a character with a prescribed talent. Often this means that the character themselves would be better going with an ability check. That is, a thief with a 16 DEX would be better off rolling 5d6 vs. ability than trying to roll a single d6 with a 2-in-6 chance. Again, this makes ability scores matter more than class abilities, which to me is a fatal flaw. On top of that, the GM has to make choices about when to call for 3d6, 4d6, or 5d6 rolls. 

d100 ≤ Ability (rows 7)

This method dramatically reduces the chance of success for "unskilled" rolls. It's a nice conservative way of doing things. It's also kind of obvious; your ability score is your % chance to succeed. Note that it's pretty rough if you are calling for rolls for things like running across a felled-tree bridge without slipping. In other words, only call for rolls when things are very risky. But overall I like this method because it makes rolling vs. ability score almost universally worse than rolling a class-based ability.

Dataset 2: showing methods on the x-in-6 or vs. 6 scale

Simple x-in-6 Check (row 1)

This method is probably the simplest and best. Most of the time the chance should be 1-in-6 (below the baseline) unless the character should, in your estimation, be naturally good at the task (perhaps considering a high ability score as a reason to increase the chance) or if the roll is for more of a die-of-fate kind of thing (like the prescribed method for triggering traps, p. 109 of the OSE Classic tome).

The Need a 6 Method (rows 4-7, shaded)

A final method is to have players roll d6s based on their ability modifier. If the ability ≤ 0, roll 2d6 and take the worst result. Otherwise roll a number of dice equal to the modifier (1d6 for +1, 2d6 for +2, 3d6 for +3). Success happens on a 6. The odds play out that only a +3 is better than a class ability.

d6 Modified by Ability ≥ x-in-6 (8 and below)

I have come to the conclusion that calling for a d6 roll modified by ability is also a bad idea. It feels intuitive to me, but it may force you to set various difficulties (sometimes over 6) and is still superior to the baseline 2-in-6 chance. It's just wonky. The less said about it the better, but I included it because I have done it. It seemed like a good idea at the table, but it wasn't. If you are going to do it, the TN should always be 7 or higher so it takes a +2 to be as good as a class ability, but this means people with no bonus automatically fail.


I think setting a simple x-in-6 chance is best. Personally, I would make this a roll-high thing, and pick a target of 4, 5, or 6 (easy, average, hard). I wouldn't let players roll for things that are exclusive class abilities. If I did let them roll for something like that (i.e. Hide in Shadows or Move Silently) that the difficulty would be 6, but it would require favorable circumstances for the character to even get the chance.

Friday, February 11, 2022

In the Beginning - the Alignments


In the beginning everything was - endless primordial goo that morphed from one form to another without direction. The Lords of Chaos, those intelligences with a strong enough will to impress the goo into shapes that lasted for some time each fashioned their own reality. Some inhabited them, their presence feeding energy into the shapes for long eons. Others abandoned their creations to the long death, as their shapes morphed and decayed over tremendous gulfs of time machine inexorably back to the goo from which they came. Some of these fickle lords created one new reality after another for themselves, feeding their massive egos and seeking a thousand pleasures. Others grew tired and began their own long slow marches back to entropy. We are left to make our own ways as best we can. Like the gods, we can create our own realities, according to our strength. We can count on nothing from the gods and can expect to find unhappiness where our ideas and theirs inevitably clash or wild gain where our interests happen to align.


In the beginning there was nothing. The God of Law decided to form a universe out of the nothing and their own material intelligence, creating a foundation upon which one intricate design after another was formed. Each increasingly beyond the ability of mere mortals to comprehend, these designs were set in motion by the Creator, who had by this time given birth to other gods, angels, and demons, and assigned them each to a specific role as guardians of creation, as well as giving each a set of laws by which they must behave. In each age some of the designs of the supreme creator, to which he gave free will, depart from their roles and the laws set down for them. Disobedience leads to errors in the system, which give rise to pain and grief and displease the creator. If we obey the clear and present laws, we live in happiness and peace. If we disobey, out of a selfish need to further our own interests at the cost of others, we are doomed to unhappiness and punishment.


We cannot know what was in the beginning, just as we cannot know everything that comprises our present realities. Life is best when we stop striving and feeding extreme viewpoints. There is only this life and it is best lived by working to gain/engaging in what pleases us without causing undue harm to others or our own bodies. There is not good or evil, no objective truth, only the eye of the storm where all conflicts coalesce into peace and stability.

Tuesday, October 26, 2021

Into the Odd: The Greenman of Darling & The Iron Coral

 Into the Odd, Session 1 (one shot that might lead to more)

Five workers from the Rumfield's Redcake factory ("perfect at nine, noon, and nightfall!") rescue the Greenman and explore the Iron Coral. Chargen and rules introduction included.

Rumfields Redcake factory

Practically perfect at nine, noon, and nightfall!

One-eyed Jack is a guard trying to earn enough money to set up his younger siblings. Ansovald Widenfield is a son of the factory owner with a supervisory title and zero interest in the humdrum factory life, oh and he has a pet eagle named Mort. Shemp works on an algae boat with his dad and son; their boat was recently repaired with money borrowed from the bank. Biltong is a dangerous drunkard who works in the hell of the algae drying room. He carries around a bomb and thinks about sabotage. Lemmy Reeves works in the forming room and has a gambling habit. He also has a 'magic key' that gets him trough any door/wall. 

The sign of the Pickled Herring

After work on Friday the group visits their regular pub, the Pickled Herring, to collect their factory benefit of a "daily dram." Responding to a commotion coming from outside the tavern that causes the spit dog to turn the meat too fast and hurl hot grease at the patrons, the crew become embroiled in an altercation between a fleeing boy with a glowing green beard (Charlie Brumfield aka The Greenman aka The Wee Man of Darling aka The Leprechaun) and some ruffians who work for Dr. Mysterio's Singular Sideshow: August Chop, a portly man with an iron leg; Junas Jongler a head carnie who wears a plum-colored coat with shiny brass buttons; Rolly, a master of fisticuffs; and Pipp Horrican, a youth with a wispy mustache, piercing blue eyes, and an annoying pug. Ansovald recognizes Charlie from sideshow posters and understands his monetary value. 

Carnies chase the sideshow escapee - The Wee Man of Darling

Altercation highlights: Shemp drinks everyone's dram in the commotion. Biltong skips out without paying his overdue bar tab. Jack puts the portly August on a whip leash and shoves a pistol barrel into the seam of the blustering gentleman's trousers. Ansovald is made a fool by his belligerent eagle refusing to attack Rolly. Rolly blackjacks the Greenman but ultimately the carnies back off. The factory workers have likely made a powerful enemy.

Once rescued, Charlie tells of how he got his beard (touching a glowing orb in the Iron Coral), how his parents sold him into servitude and separated him from his twin sister, and how his life now consists of getting beard hairs pulled out for the financial benefit of others. The workers decide to explore the Iron Coral for arcana, as they have until 1 pm the next day to get back to work. Their boss attends secret "star cult" rites in the wee hours of each Saturday, so shuts the factory down (other than hiring a crew to grease the workings) the next morning to give him time to recover. Charlie agrees to lead them to the place since it is on the way to his home town of Darling.

In the coral the crew find an underground tunnel with clear walls that look into the ocean, touch a glowing sphere that hurls One-eyed Jack against a wall, and fight a glittering woman who seems to guard a couple of handleless iron doors.

Highlights include Biltong falling down some wet stairs and Lemmy chucking his canary at a glowing cloud, and Jack sprouting a red, glowing, fleshy orb in his empty socket after being thrown into the wall by the sphere. The fight gets nasty as the woman is hard to damage, but seems to sap away the will of anyone she squarely hits with her sparkling claws. Lemmy's key is used first to try and turn the woman corporeal (a clever idea that failed) and then to bypass both doors. Several characters are overwhelmed by damage: One-eyed Jack (now Red-eyed Jack) and Lemmy both get taken out of the action. Lemmy manages to first pass his key to Shemp who recovers two gauntlet like arcana from the locked rooms. In the fight, Biltong tries putting on both gauntlets and smashing them repeatedly into the woman. They trade blows until the woman explodes - her glittering form dissipating into the air of the room. 

After getting the injured back on their feet the crew return in time for their next shift, but tired, drained, and hurt as they are, several pick up "demerits" for their lackluster performance on the job. (Current demerit count: 2 for Biltong and Ansovald. 1 each for Shemp, Lemmy, and Jack. 

Tuesday, July 6, 2021

Knights of the Road: Capsule Review

This tripartite micro-zine takes the bones of Electric Bastionland and fleshes them out with a vague, early 20thc weird west setting. Sound cool? It is. (You can get it here.)

When I first heard about this zine I got the impression that the player characters were hobos, partly because the GM was called a "Conductor" (as in train conductor) and partly because they are roaming around 1920s (?) America on rails. But the characters aren't just tramps looking for a handout. Instead, they are part of an order of vagrant-knights who move around undoing evil-wrong-bad things. Also, America isn't really America; the setting is a fictional analogue of America. The time is equally hard to pin down because of inconsistent references to technologies. Even so, the result is a charming (and liberating) mass of ideas. Vampire lords run the rails. Cryptids like chupacabra and bigfoot infest the darker corners of the world. The landscape is peppered with haunted abandoned movie sets and alien crash sites. Great stuff.

I'm going to pick at the product a little in the next few paragraphs, but let me make it clear that I think this is a brilliant little zine and fills a niche you rarely see filled.

The product itself is readable and mostly clear. For $5 (digital) it's a bargain. The art is a little sparse but cool and proper for the setting/overall feel of the zine. There are quite a few typos and grammar gaffs, but nothing that would really throw you for a loop. I don't have the physical product (yet) but I hear they are quite small. The title fonts are nice, but I found the body text font a little clunky. 

One other thing I want to note that is both a positive and perhaps a negative - the zine includes an example of play. This kind of thing is rare for zines, so I applaud the inclusion. However, the example is almost laughably condensed. It's basically a whole game session (or at least a major encounter), start to finish, in two micro-pages. Even so, it gets the idea across, including the fast-and-loose nature of conducting a light RPG like this. 

For a zine-game, KotR is surprisingly complete. A full book of monsters, quite a few story hooks, GM advice, examples, etc. It really covers the bases. I highly recommend it and would love to run it for one of my gaming groups. 

I'll leave you with a tiny bit of the awesome, full-color map included with the KotR. 

Monday, June 28, 2021

Agramabug Capsule Review

Federico Volpini recently shared his very cool bug-centric mini-setting for Troika! with me. The writing is great and the art reminds me of the Tenniel illustrations from Alice in Wonderland. The world is full of crazy, flavorful details: freon zombies, punk foodies, dust monks, a bug pope, a weird landscape of human refuse... great stuff. (You can pick it up on itch.io.)

A few very minor criticisms. The introductory paragraph is a bit of a cold start, throwing you right into the setting. So just to state the obvious: Agramabug is an RPG setting compatible with Troika! in which communities of insects scrabble over the discarded wastes of humans hoping to attain power, security, and prosperity. The text is also a bit tightly-spaced, but then I think my 53-yo eyes are just always craving a little more white space these days. My 23-yo self probably would have loved the denseness of the design. 

Is there such a thing as too many poo jokes? I feel like the setting is scatalogical to a degree that would get a little old. What else matters to bugs -- water, pollen, seeds? It bears thinking about before you throw players into the setting.

Back to the good stuff. The lists. Oh my gawds, the lists. I have a soft spot for lists because a designer can pack so much setting into them, and that's just what Fredrico did. The classes are great too, and if you know Troika!, you'll know that this is its other primary tool for communicating setting.

The world is both comical and dreary at the same time, if that's possible. It could be played as grimdark or wildly comic, or both. My first addition would be some hippy-granola bugs who live on a sunny hill filled with dandelions, just to give a bit of contrast to the extensive landfill that Fredrico provides.

Perhaps the highest bit of praise I can give to Agramabug is that I want to play it. My default reading stance after a few paragraphs was "how I would run this" not "is this any good?" So clearly I made up my mind on the latter pretty fast.