Randomization in chess and roguelikes

 

Chess960: chess with a random setup

Chess960, also known as Fischer random chess, is a variant of standard Western chess in which the home-rank pieces (that is, all pieces except the pawns) are given random starting positions, making it a type of shuffle chess. Published in 1996, the game has increased in prominence in recent years, with 2019 seeing the first official FIDE World Fischer Random Chess Championship.

The effect of varying the starting positions is to reduce the dependence on memorizing openings. This potentially quite interesting game is sadly marred by sharing a name with its creator, Bobby Fischer, the Holocaust-denying Hitler fanboy of the chess world. To avoid giving this vile man any more respect than he deserves, which is to say none at all, I will be referring to the game as Chess960. "Fischerandom" and "Chess960" are both variant names accepted by chess programs.

 

Using polyhedral dice for Chess960 starting positions

Starting positions are mirrored between the two players, so the randomization process for Chess960 needs to only fill in one player's home rank. The second player's starting positions are implied by the first player's.

The starting positions of the pieces have the following constraints:

• The player's two bishops must be on squares of opposite colours.
• The player's king must be between the two rooks (to allow castling as in standard chess).

When a computer is not available, we can use a set of polyhedral dice (sometimes called "roleplaying dice" or "D&D dice") to determine the starting positions.

Image 1. The pawns always start at the same positions.

A rank on a chess board has 8 columns/squares, 4 of each color. Thus, there are 4 possible positions for each bishop. Using polyhedral dice, this can be rolled using two d4 (one of each colour).

Let's assume we rolled a 2 and a 2, placing the bishops on columns c and d.

Image 2. The bishops have been placed.

6 squares remain, and the queen is placed next on any one of them. This can be rolled using a d6.

Let's assume we rolled a 5 on the d6, placing the queen on column g.

Image 3. The queen has been placed.

Then, with 5 squares remaining, the two knights are placed randomly on any of them.

Roll a d10. On a result of 1-5, place the first knight on the corresponding free square, and then the second knight on the next free position immediately to its right. On a result of 6-10, place the first knight in the same way (treating a 6 as a 1, and so on), but place the second knight two free positions to the right, instead of one. Wrap the second knight around, so that if there are no more free positions on the right, start counting from the left again.

So, if our free positions are abefh, then the results on the die correspond to the following placements:

d10	First knight	Second knight
1	a	b
2	b	e
3	e	f
4	f	h
5	h	a
6	a	e
7	b	f
8	e	h
9	f	a
10	h	b

Let's assume we rolled a 10 on the d10. The knights are then placed on columns h and b - or, equivalently, b and h.

 

Image 4. The knights have been placed in b1 and h1.

The 3 remaining squares can only be filled one way, due to the constraint that the king must be between the rooks.

Image 5. The rooks and king have been placed. All positions have been selected. Now, all that remains is to fill out the other player's positions as a mirror image.

Image 6. The final starting positions for both players. White to play.

There are 4 x 4 x 6 x 10 = 960 different starting positions.

Using our example method of generating these positions with polyhedral dice, four dice are needed: a black d4, a white d4, and a d6 and a d10. Or, you can roll the same d4 two times in sequence, once for each bishop.

The method for determining knight positions given here is only one of many possibilities, chosen here because it avoids rerolls and redundancies and seems like something I could remember. I recommend using any rule which you find easy to remember to avoid having to consult a player aid.

 

Other randomized chess variants

Transcendental chess is another randomized chess variant, invented in 1978 by Maxwell Lawrence, (a full 18 years earlier than Chess960). In transcendental chess, the constraint on the rook and king positions does not apply, and castling is removed. Rather than mirroring the board, each player's positions are determined independently. Additionally, a player may use their first turn to swap two pieces on their back row, instead of making a move. As many setups will have one side starting at an advantage, it will perhaps be sporting to play two games for each setup, changing sides in between.

D-chess is similar to transcendental chess, but rather than playing two games, one player gets to choose the side they think is stronger, and the other player gets the option to swap two pieces and also gets the first move.

 

Is there room for randomization in chess?

Traditional chess is fully deterministic, with no random factors. Everything depends on the players' decisions. In many other games and sports, much of the excitement comes from the combination of luck and skill. Their interplay allows for bold risk-taking and dramatic upsets. Far from the usual derision of chance as a factor that makes skill completely irrelevant, taking the right risks at the right time is a skill in itself. Reacting to unlikely chance occurrences can also be a kind of skill, as can knowing and regulating the impact of uncertainty on one's strategy.

In the Wikipedia article linked above, you can read quotes from chess grandmasters on shuffle chess. Some even go as far as saying it's "the future". Reading between the lines, one can get the impression that the game's lack of excitement and human drama is hampering its public profile and influx of new players. Could adding a chance element make chess a bit... well, less boring?

The interplay of chance and skill in games can be broadly divided into two categories: chance that comes after a player's decision, and that which comes before a player's decision. In other words, "randomness of outcome" or output randomness, and "randomness of setup" or input randomness. For example, a chess variant in which the attacker must roll a die to determine the success of a capture has output randomness. This kind of randomness promotes the correct gauging of risk, but it typically has a very large effect on the game's outcome. 

Meanwhile, a chess variant with randomized starting positions would be in the second category, having input randomness. The initial positions may have a large effect on the odds of wining, but beyond that, the only measure of skill is in how the players react and adapt to this new and surprising situation. The player makes an informed decision, and its result is deterministic.

It may be noted that within board games, the output randomness design pattern is more common in American-style boardgames such as Risk, which often include direct conflict, and combat resolution mechanics resembling wargames or Dungeons & Dragons. There, uncertainty is a tool to heighten drama. European-style games, meanwhile, have little or no output randomness, and typically less hidden information. A Eurogame may include input randomness through a randomized initial setup, but from there onward the players' decisions have largely deterministic results. This typically makes for a game that requires careful planning.

Chess, while considered an early wargame, has neither the elements of dice-based combat resolution nor hidden information (fog of war) featured in many wargames starting with the 19th-century Kriegsspiel. It could be argued that adding input randomness to chess through randomized initial setups would turn it into "a Euro-style boardgame".

 

Genres & generations

Arguably the most important games of the 20th century were chess, poker, and Dungeons & Dragons (in increasing order of randomness). D&D's influence has been huge not only in traditional roleplaying games but also in video games and board games. Its dice-based combat system has been passed down through Rogue, Nethack, Dungeon Crawl, Diablo, Elder Scrolls, Final Fantasy, and so on - essentially, the entire "RPG" videogame genre, and beyond.

Although D&D came from the wargaming tradition, it is a cooperative game, not a competitive one. Unlike D&D and the mostly single-player RPGs it inspired, some games in this lineage are competitive. Dota 2 is a multiplayer game of conflict with quite clear D&D-style elements. Dungeon Crawl: Stone Soup is a single-player game in the roguelike genre which is played in competitive tournament formats.

 

Chesslikes?

Interestingly, while the roguelike genre is known for its large degree of randomness, in recent years there has been more experimentation in minimizing output randomness, removing the dice resolution of combat in favour of deterministic models. What is left is just a randomization of maps - input randomness. Often, the entire map is revealed to the player, reducing hidden information as well. This could be seen as a move towards a "Eurogame-ization" of roguelikes. Examples include 868-HACK, Hoplite, and HyperRogue, in which the levels, enemy positions, and powerups are random, but attacks cannot miss and damage is predictable. These games have been described as abstract roguelikes, "tactical puzzles", or even feeling "chess-like". Here, chess-like is being used as an adjective - for now at least, chesslikes are not a recognized game genre.

But... what if? 

 

Image 7. A screenshot from 868-HACK by Michael Brough. Source.

Chess, with its deterministic head-to-head battles, and roguelikes with their iconically chaotic single-player experiences may seem as far apart as games can be. But at their core, both are games of tactics and strategy that play out on a square grid. Both require geometric pattern recognition - and heapings of experience and knowledge. Both are games that can hold a player's interest for 20 years or more.

Perhaps as chess begins to include more random factors, and roguelikes lessen their output randomness, we will see the two genres move closer and closer until they almost seem to merge. Could we even begin to see roguelikes which play out as a battle between two opposing players? Who knows. The future, for now, is under a fog of war.

OSR Idea: Random Backgrounds as Consolation Prizes

TL;DR: Have several tables of backgrounds; characters with low ability scores roll on better tables.

Rolling for stats

Sometimes it can feel like the OSR has a love-hate relationship with the 3d6 down-the-line method of generating ability scores. Lamentations of the Flame Princess allows swapping one pair of scores, which I think is great - sometimes you just want to play a fighter. It also lets you reroll everything if the sum of ability modifiers is negative. 41% of B/X characters have a negative total modifier. In other words, in LotFP, after you've rolled up scores, marked the modifiers, and added them all up, 4 out of 10 times you have to do it all again. (Well, you don't have to - it's entirely optional - but why wouldn't you?)

Stars Without Number, in lieu of swapping scores, allows you to replace one score with 14 (+2). That seems more reasonable - it ensures that whatever kind of character you want to play, there will be at least one thing you're not entirely terrible at. It's also self-limiting - if you already rolled kickass scores across the board, bumping one to 14 isn't going to make as much difference. (SWN also shrinks the modifier range from ±3 to ±2, which seems like a good idea.) There's also the option of taking an array (14, 12, 11, 10, 9, 7) instead of rolling.

But somehow, these methods - particularly the "total do-over 41% of the time" one - seem a bit like admitting defeat. Why do we roll scores again?

Because we like the variation in characters - that jolt to the imagination that something completely human-planned cannot deliver. Also, because it's much faster than having everyone minmax which number to place where. This is a game about interacting with a world, not about deckbuilding. Roll roll roll, pick a class, go. Discover who your character is during play - don't agonize over it in the pre-game.

Maybe there's something we can hack up to keep the straightforwardness of rolling scores (no do-overs) while softening the blow of crappy ones?

Random backgrounds

Backgrounds can help give flavour to characters that can otherwise feel a bit like blank pawns, and act as a seed for roleplay. A background can be tied to a (pre-adventuring) profession, and have minor mechanical bonuses: some extra starting items, a skill increase, or perhaps a "mini-feat".

The problem with entirely random backgrounds is that the more backgrounds you write, the more difficult they are to make roughly equivalent in power. Vice versa, if you follow a restrictive formula such as "all backgrounds get +1 to one skill", you're both going to run out of suitable ideas, and will be unable to fit many setting-appropriate backgrounds to this mould.

And if you don't make them strictly equal? What if one background gets +1 to CON modifier while another can... tell when it's about to rain? It isn't game-breaking in itself, but can feel a bit unfair - even more so if the characters that rolled awesome scores also happen to land on the best backgrounds. Meanwhile, the poor sod with a -5 total modifier gets to be Background: Dirt Farmer. (Or a mudlark, which is a child that scavenges among the mud and gets pelted with coins and laughed at as they dive into the mud to catch them.)

Consolation Prizes

Here's an idea for a solution: tie background table rolls to ability scores, but give them an inverse relationship - the worse your scores, the better backgrounds you can roll, as way of a consolation prize. Now the designer no longer needs to balance backgrounds by making them all equally good - they're freed to deliberately design a power continuum, and it will be offset by ability scores. Now even players who rolled terribly can look forward to playing their new character.

(As a guideline to designing these backgrounds, they should never affect ability scores or ability modifiers. Those have already been rolled for, so a "Background: Strongman - +2 to Strength score" does not make sense; it's redundant. However, a mini-feat that affects a secondary stat is totally fine: for example, shepherds can get a +1 to attacks with slings.)

Tiers

To divide generated characters into tiers, we need a mathematical benchmark to estimate their intrinsic value. One possible (albeit naive) benchmark is to simply sum up all the character' ability modifiers. When six stats are generated by 3d6 each, their ability modifiers per B/X summed up have a normal distribution with the average at +0 total modifier:

The possible results can be divided into an arbitrary number of bins of manageable probability, such as:

Total Modifier	%
-4 or lower	5.8	Tier 5
-3 to -2	19.1	Tier 4
-1 to +0	34.1	Tier 3
+1 to +2	28.1	Tier 2
+3 or higher	12.9	Tier 1

We can give each bin a tier. The higher the ability score total, the "better" the character inherently is. (In actuality, not all abilities are of equal worth, and their worth does not scale identically with modifier or score. For example, in my game, each point of Strength score gives you an item slot and each point of Constitution score makes you less likely to lose consciousness, whereas with Intelligence only the modifier matters. The benchmark I'm using here ignores such considerations. You could also look at highest scores, lowest scores, or whatever. If your game is one of those weird roll-under-stat ones with no modifiers, maybe use sum-of-all-scores as the benchmark.)

So 5.8% of randomly generated characters will have very bad scores, putting them into Tier 5, and so on. Now, we can write a different table of backgrounds for each tier of character, with intrinsically "worse" characters rolling on cooler, weirder, and more powerful background tables.

Tier 1:

These characters have great scores - they don't need an impactful background. They are the unskilled professions as well as those skilled professions whose craft has little to no impact on the game: porters, farmers (dirt or otherwise), bakers, coopers, chandlers, calculators, mudlarks... even for their bonus starting items, the best these people can hope for is a single tool (with no immediately obvious use in the dungeon) and a bag of turnips.

Tier 2:

The professions that have a small game impact, mostly during downtime. For example, blacksmiths could make their own armour for half price. These are unlikely to come up very often, but are not utterly useless, either. They could be skills that any character can learn in your game, given enough investment. You could also put backgrounds that have no skills but very good starting items into this tier. Some may have dungeon-applicable tools.

• Noble: No skills or mini-feats. Starts with 200 gp and a bottle of fine wine.
• Blacksmith: During downtime, can craft armour, melee weapons, and other metal items. Material cost is half of the item's listed price. Work takes one week per 10 gp of listed price. Starts with a hammer and a bar of iron. Anvil sold separately.
• Bowyer: As Blacksmith, but can craft bows, crossbows and ammunition.
• Miner: Count as two people for excavations (three if you're a Dwarf). Starts with a pickaxe and a lodestone.
• Masons: +1 Architecture. Starts with a sledgehammer.
• Scribe: +1 Languages. Starts with  parchments, quills, and ink.

Tier 3:

These are professions whose skills have a clear impact on the game - for example, anything that boosts lockpicking/Tinker, Bushcraft or Search. Situationally useful (not just during downtime) mini-feats may also be placed into this tier. Often, these are combined with useful tools.

• Actor: +1 to reaction rolls with humanoids. Starts with a mask and makeup.
• Officer: +1 to follower morale. Starts with ceremonial rapier.
• Falconer: Has a trained falcon that follows commands. Starts with a falcon and a mail glove.
• Barber-surgeon: +1 Medicine. Starts with razor and leather strap.
• Brawler: Improvised weapons count as regular weapons.
• Bounty hunter: +1 Bushcraft. Starts with a hound and rope.
• Bear-leader: +1 to reaction rolls with beasts. Starts with rope and animal feed.

Tier 4:

Backgrounds with mini-feats that give a boost to combat capability or survivability. Rare and expensive tools may be given as starting items. For example:

• Shepherd: +1 to hit with slings. Starts with a cane and a bag of wool.
• Poisonmaker: +1 to saves vs. Poison. Starts with 4 vials of poison.
• Diviner: Can cast detect magic once per day. Starts with crystal ball and deck of cards.
• Occultist: Can cast summon once per day (as Caster Level 0). Starts with curved dagger and black candles.
• Lumberjack: +1 to hit with axes. Guess what starting equipment.
• Acrobat: Fall damage is reduced by 20'.

Tier 5:

Go wild here. These characters have crap scores, so give them something surprising. Something that makes a big impact on the way the character plays. Got a class that's a bit more gonzo than the others (like the Skeleton Adventurer or Half-Troll) that you're not sure is entirely balanced and don't want players to be able to pick freely? Stick it here. "You're a skeleton in a hooded cloak, that's your background."

You can populate this tier with backgrounds that are plot hooks in themselves, or unique things that can only be rolled once.. Hell, put some superpowers here. "Dragonsoul: once per day, you can use a breath weapon that deals [Lvl]d6 damage." The stuff that a WotC game would let anyone pick willy-nilly, spoiling the mystique: those descended from the lines of elementals or gods! The insect-folk from two towns over! Soulless people who are invisible to the undead! Werewolves! Wielders of a runesword that grows stronger with every soul it eats! Weird mutants! Their low stats will mean they might not survive that long anyway. And hey, awesomely powerful individuals being physically weak is very swords & sorcery.

The Way to Do Ascending Armor Class

Why Ascending?

As a DM who loves the OSR, you probably want to get as many people into it as possible. Thus, if there is something you can do to make the game more accessible without any functional changes, you should probably do it. For example: using ascending armor class, which the vast majority of players are more familiar with than descending armor class.

Of course, old adventure modules you will use at the table descending armor class. In this case, it's easy for you, as the DM, to look at the page and convert the number in your head. Far easier and faster, at least, than having to explain attack tables or THAC0 to each new player.

The Full Score

Conversion is as simple as subtracting the old AC or THAC0 value from your conversion base, which is a fixed number. So what do you choose as this base? If the choice can make the mental arithmetic even a tiny sliver easier for you, then it will save a lot of time in the long run. I find that a round number like 20 is slightly easier to subtract from.

So your conversion formula would look like this:

Desceding AC = 20 - Ascending AC
Attack Bonus = 20 - THAC0

Thus, if you're reading an old module and see a monster with 5 AC, you tell the players that it has 15 AC. Monster attack bonus is an even easier case: you don't even need to check the attack table if you can memorize how monster HD relates to attack bonus. In our case, that is exceptionally easy - monsters have an attack bonus equal to their HD! (At least up to 8 HD - the B/X attack progression slows down at very high HDs.) That means that monsters with less than 1 HD have +1, and so on. "Normal men", which I like to think of as "level 0 types", have an attack bonus of +0.

Very clean, right? It's kind of intuitive that all 1st level PCs attack at +1, and thus all "normal humans" - those who haven't gained a class - attack at +0. Anyone with a class attacks at +1 (you can think of 'monster' as a class).

If you chose another number as your base, say 19, then level 0 types would attack at -1? That's weird.

So if 20 is such a good base, surely most modern AAC-using retroclones use it? As it turns out, no.

The Big Comparison

Swords & Wizardry offers both descending and ascending AC. Old-school descending AC and attack tables are the same as B/X - unarmored AC is 9. In ascending AC, unarmored is 10. This means that to hit an opponent with 20 AC, a 1st level Fighter needs to roll a 20 - as if her attack bonus was +0. So does that mean normal humans have an attack bonus of -1? The book doesn't say. Is the authors's sole reason for choosing 19 as the conversion base that an "unarmored base AC" of 10 looks pretty? If so, I don't think that's a very good reason.

B/X Essentials only includes descending armor class, but its upcoming refinement Old-School Essentials adds an option for ascending armor class. It sets unarmored AC at 10, taking its cue from Swords & Wizardry.

Lamentations of the Flame Princess goes in a completely different direction. There, unarmored characters have 12 AC (ascending). In other words, the conversion base is 21 (21-9 = 12). To match, Fighters attack at +2. But all other PC classes only attack at +1, so they've been demoted to "normal humans" - while NPCs themselves attack at +0! Overall, everything is harder to hit, to suit the game's greater emphasis on horror. I actually think this is a bit of a trap for new players, who get recommended LotFP as the "default, generic" OSR game, but are faced with a lot more frustration than anticipated. Buyer beware!

Basic Fantasy RPG, for one, does it right. PCs have an attack bonus of +1, normal men of +0, and unarmored AC is 11! Hooray! For everything BFRPG does that I disagree with, here is one part where they knock it out of the park: designing with the actual use case (on-the-fly conversion) in mind, rather than for a surface appearance of elegance.

I don't think anyone cares if unarmored AC is a nice round number - when it goes on the sheet, it gets modified by their equipment and Dexterity anyway. Basic Fantasy: 1, Swords & Wizardry: 0.

Of course, if you use the above system and play a S&W module that lists both DAC and AAC, you will need to either use the DAC for conversion, raise the quoted AAC by 1, or use the AAC as-is and be happy with the fact that monsters are nerfed by 1 AC, which is probably perfectly fine.

(Another tiny caveat: the above only talks about converting B/X and OD&D materials, where unarmored is 9 and Fighters have THAC0 19. AD&D actually changes these, moving unarmored to 10 and giving Fighters THAC0 20 to match. If you use the above to convert the AC values from an AD&D module, you will end up nerfing the monsters by 1 point. And that's probably perfectly fine too.)

Monster: Spell Scroll Mummy

A strange mummy wanders the sandy wastes, not bound to a tomb like others of its kind. Even the burning sun seems to dim in its presence. If you choose to go near it, you notice strange symbols on its wrappings. Magic-users immediately recognize these as spell scrolls.

HD 6
AC 15 [descending AC 5]*
Atk #1 touch (1d12 + spell drain)
Mv 60' (20')
Sv 13+ (or as F6)
Al Chaos
XP 500
NA 1 (1d4)

The spell scroll mummy hungers for magic. It can smell spellbooks and spell scrolls and will hunt down and attack anyone carrying them. It will leave alone travelers that have neither and wander back into the desert, unless attacked.

If the mummy decides to advance, anyone who sees it must save vs. Paralysis or be paralysed with terror until they no longer see the mummy or the mummy attacks someone.

The mummy's wrappings contain 8 spells total: three of 1st, three of 2nd, and two of 3rd level.

Each hit die's worth of cumulative damage the mummy takes destroys one of the scrolls. If the mummy takes fire damage, a scroll explodes, casting the inscribed spell at a random target. The scrolls are not harmed by non-physical damage such as magic missile. Clever players may find other ways to disable the mummy and retrieve the scrolls from it without destroying them.

If the mummy's attack hits a magic-user or similar spellcaster, the spellcaster loses one of their prepared spells, if any, starting from the lowest level slot available. A spell slot absorbed in this way heals the mummy for 1 HD's worth and magically scribes the spell into its wrappings.

The mummy cannot absorb divine (i.e. clerical) magic and has no interest in it.

As an undead, the mummy is immune to poison and mind-affecting spells.

* For ascending AC, I use unarmored = 11. This makes converting old material easy: AC = 20-DAC, base attack bonus = 20-THAC0. A normal human attacks at +0, and most monsters' attack bonus equals their HD.

OSR Class: Skeleton Adventurer

I guess the Trollkin class set my mind on the track of "slightly monstrous adventurers with death-avoiding abilities". I googled "OSR skeleton class" and found only this: https://www.necropraxis.com/2014/02/06/skeleton-class/ so consider this class inspired by Necropraxis's. Essentially I've codified a bit more what it means to be an undead PC, and made the class rather more party-dependant.

The weird thing is, I don't even like monstrous PCs. Or perhaps I just don't like them being "core" options at the front of the book. I think the upfront choice presented to players should be simple. I see more exotic races/classes as something to be "unlocked" as the campaign progresses and more is learned about the world and alliances are forged - their availability depends on the PCs' actions in some way. Or for use in specific cases, like when a character becomes hopelessly lost in a necromantic dungeon.

Anyway, it's just your standard skelly. Fragile and misunderstood, dependant on others. Some weaknesses, some immunities. There is a bittersweet undertone to being brought back to “life”, because you know it’s not going to last forever.

Class: Skeleton Adventurer

 Choose either Fighter or Thief/Specialist. Your HD, Attack, Saving Throws and XP requirements are the same as that class. If you chose Thief/Specialist, you get their skills, but if you chose Fighter, you don’t get any special maneuvers they may have. Magic-Users cannot become Skeleton Adventurers, because their magic energies have a destructive interference with any necromantic aura that may be present in the environment.

Spooky: You creep people out, though they’re not quite sure why. When wearing concealing robes and a hood, you have -2 to reaction rolls from civil society. When not concealed, you will be attacked on sight.

Due to your hollow voice, the reaction penalty applies even when using sight-based illusions, but illusions that also have an auditory component will negate the penalty.

Brittle: You take an additional die of damage from bludgeoning and crushing attacks, e.g. hammers, wolf jaws, and falling stones.

Unliving: You do not not need to breathe, eat or sleep. You are immune to sleep effects (but not charm effects), diseases and most poisons. You gain no benefit from magical healing, but can repair yourself during downtime at the usual healing rate. Unintelligent undead will ignore you unless you attack. Also, you can feign dead perfectly.

Meatless: You are very light, weighing only about 10-20 pounds. When riding piggyback, you only take up two inventory slots (or the equivalent of two standard swords).

Turn Resistance: You are affected by Turn Undead as an undead of HD equal to your level, but get a save vs. Magic to resist a successful turning.

Well-Articulated: You can detach a limb to use as a club for d6 damage.

Reconstitution: When reduced to 0 hit points or below, you crumple into a pile of bones. You may can be rebuilt and brought back to unlife. An attempt to rebuild your skeleton takes one turn, and requires an Intelligence ability check (or Medicine skill check, if your ruleset includes it) to succeed, though the cost of failure is only wasted time. On a successful check, you return to unlife, but lose 1 point from your Constitution score.

After reconstitution, there is a 1-in-6 chance that a random limb is missing, but you can always scavenge other peoples’ bones to find a replacement.

Differentiating Spellcasters: Spell Orbs, Elven Mind-Palaces, and more

These are some of the kookier ideas I’m kicking about. The Elven one, I think, is a really flavourful and small change that makes them more Moorcockian/ Melnibonéan, which I dig. The Cleric change is something that makes sense to me fluff-wise, but I’m not sure if it might break the game too much - please let me know what you think. The Magic-User one is the most kooky, and has the biggest impact on how the game plays, so I've saved it for last. Any of these can be implemented separate of each other. As always, nothing is playtested until stated otherwise.

Clerical Miracle-Working

Spontaneous Casting: Clerics no longer prepare spells. They can spontaneously cast any spell they know, which “spends” the corresponding spell slot. As usual, sleep and meditation is required to recover spent spell slots.

Elven Sorcery

Casting: Elves are innately sorcerous. Instead of using Spell-Orbs (see Magic-User), spells simply emanate out of an Elf's hand, though they share the Magic-User's spell list.

Mind-Palaces: Instead of a spellbook, Elves carve their spells into their personal Mind-Palace, which exists in the plane of dreams.

Transcribing a new spell into their Mind-Palace requires a long and deep trance and the use of special incense and potions. In terms of time and gold cost, this is the same as for Magic-Users. However, unlike a spellbook, the Mind-Palace cannot be physically stolen or destroyed (although astral travel into the plane of dreams may enable one to vandalize an Elf’s mind palace, or steal spell formulae). An Elf’s Mind-Palace starts with only the Read Magic spell.

Preparing & Learning: Elves still prepare spells into slots, which is done during their nightly sleep/trance. Each time they gain a level, an Elf learns a new spell of a level of their choice and adds it to their Mind-Palace at no gold cost (though the time requirement still applies).

Magic-Users’ Spell-Orbs

Preparing: When Magic-Users prepare spells (which requires access to their spellbook), they create a one-use physical object for each prepared spell called a Spell-Orb.

Appearance: Assume a Spell-Orb takes up roughly one "slot" of inventory, or about the same space as a flask of oil. Most Spell-Orbs appear as glass balls with energies swirling inside them. However, they may also be any other sufficiently sized fragile and obviously mystical object: a charm made of sticks and bones, an unstable alchemical concoction in a bottle, or a latticework of herbs and crustacean legs joined with the mixed saliva of birds and the Magic-User. A Spell-Orb may be set into the tip of a staff for convenience.

(The reason Magic-Users often wear long robes is to conceal their Spell-Orbs within the myriad folds and secret pockets, in order to prevent assailants from snatching or destroying them.)

Casting: Using the Spell-Orb requires gesturing with it, which then triggers the spell and destroys the orb. Ranged spells require the orb to be thrown, though they cannot miss; they orbs transform mid-air into magic missiles, fireballs and so on, functioning just the same as any other spellcasting method.

Other characters may also use Spell-Orbs created by a Magic-User. Characters who are not Magic-Users, or Magic-Users of an insufficient level to cast the spell, can attempt to use them with a risk of failure. When you make such an attempt, roll your Arcana skill (1+INT in 6, Magic-Users have +1) with a penalty equal to the spell’s level. Example: if your Arcana skill is 4 and you use a 2nd level spell, you have a 2-in-6 chance of succeeding.

If the Arcana attempt fails with a roll of 6 on the die, the spell is a misfire: it is triggered but with its target or effect reversed (as deemed appropriate by the Referee). If it fails on any other number, the spell is not triggered and the Spell-Orb remains unused. A character who has failed to trigger a specific orb may not attempt to use that orb again, though it is still usable by others. Thrown Spell-Orbs (i.e. ranged spells) that fail to trigger merely fall onto the ground, but when hitting a hard surface have a 1-in-6 chance to shatter. When a fallen orb shatters, it triggers the spell, targeting the space it landed in. Fallen spell orbs can also be shattered by missile attacks (AC 17 to hit). 

Unused Spell-Orbs harmlessly disappear out of existence when the Magic-User recovers their spell slots. When the Magic-User dies, each of their active spell orbs has a 4-in-6 chance of dissipating harmlessly, and a 1-in-6 chance of exploding and triggering the spell, otherwise persisting and remaining usable by others.

Gaining new spells: Spellbooks work as before: each time they gain a level, a Magic-User learns a new spell of a level of their choice and adds it to their spellbook at no gold cost (though the time requirement still applies).

(Note that only Magic-Users use spellbooks and spell orbs, though all casters still use the system of spell slots.)

Rationale

The physicality of orbs will help players unfamiliar with Vancian casting grasp the meaning of spell slots. In Vance’s stories, spells are living things that inhabit a wizard’s head through his concentration and discomfort. Now, they will be concrete things the character can hold. Also, this will make inventory management a factor for Magic-Users (particularly suited to slot-based inventory systems, and those with rules for item breakage). Allowing other characters to use orbs opens up new possibilities, but at a risk. As for shattering orbs, I’ve always liked how in Nethack et al. burned scrolls can explode, broken potions still apply their effects, and so on. It really ties magic into the environment, a real part of the world. (And, honestly, I kind of want to see someone try to jam a fireball orb down a white dragon's gullet.) Also, spell orbs once again harken back to certain concepts in Dave Arneson's early games, though I do not know how the mechanics there exactly worked. If you have good information on Arnesonian spell balls, please let me know.

Many systems try to take out the spellcasting system from D&D and replace it with something else, like spell points. None so far have produced better results in play than the original system.
I currently have no interest in redoing the entire spell system, or writing new spell lists, or most importantly, breaking compatibility with existing TSR & OSR materials. However “slots vs. spell points” is not the only parameter that can be modified in the spell system. There are at least the following parameters, off the top of my head:

1. Casting spells - the actions required to activate a spell, and any restrictions to doing so such as “no armour”, and any side effects of these actions (magical mishaps, etc.)
2. Preparing spells - when and how a character chooses the spells available for the adventure, or if they have all the spells they know available (spontaneous casting)
3. Learning spells - whether a character knows all spells on their list, or knows a subset of it, and whether there is a maximum on the size of the known subset
4. Spell resources - what is spent to use spells: spell slots and spell levels, spell points, HP drain, increasing risks, etc.

Of these, #4 seems to be the most often complained about, and most often modified. It’s also the one that needs the most work, and often breaks compatibility with existing spell lists, because translating spell levels to a shared resource doesn’t work too well. (It’s not really even the part that’s the most “Vancian” - preparation is.)

It appears to me that the other parameters - how to cast spells, how to prepare spells, and how to learn spells - are a much more fruitful area for modification. Changes to them have a much smaller interface with the rest of the rulebook - although they may still have far-reaching balance consequences during play (such as allowing Magic-Users to cast spontaneously).

With small changes like these to how your spellcasters learn, copy, prepare and cast spells, you can give them unique flavour without invalidating existing spell lists and compatibility with modules. The possibilities are endless. Imagine, for example, a druid’s spell slots each taking the form of an animal spirit when not prepared, or an elf who can only channel spells through weapon attacks, or...

Ascending Damage & Dicing With Death

The rule

You no longer have hit points. You have a Wounds tally - the higher it goes, the more badly you've been hurt. You start at 0 Wounds. Whenever you are hit by an attack, you suffer 1 Wound. (This replaces HP damage. Damage sources that would deal multiple dice of damage deal one Wound per die of damage.)

You have a Maximum Wounds number from your class table (modified by CON - note that there are no negative ability modifiers, as per this previous post, so Max Wounds is always at least 1). If your Wounds exceeds your Maximum Wounds, you must Dice With Death: roll a d20. If the result is below your current Wounds, you die. However, if the result is above your Constitution score, you fall unconscious for 1 hour.

While above your Maximum Wounds, you must Dice With Death again each time you take further Wounds. Additionally, you have -2 to attack rolls and AC.

The rationale

Dying and initiative seem to be the two topics that I re-tread over and over, no matter the system I’m playing. I recently realized that “Health” as the number of hits to kill a PC from my earlier post (which replaces rolled damage) would pair perfectly with an ascending damage system. That is, one where you tally up the damage you’ve taken on your character sheet, instead of subtracting from your hit points tally.

In the regular D&D system of HP and damage rolls, there is uncertainty at first, followed by certainty: first, you take variable amounts of damage, but once you’re at 0 HP, you’re dead (or unconscious or whatever it may be). The mechanics move from dynamic to static as play progresses. On the other hand, this proposed system of static damage (1 Wound per die) makes things… well, static and predictable at first. But Dicing With Death makes the next phase dynamic and uncertain. It flips the script of the adventure around, as it were: the uncertainty of rolling is moved to the later, higher stakes part of the game. As the adventure progresses and resources dwindle, uncertainty goes up. And, thematically, that makes sense, right?

(By the way, there exists a third system that differs from both the “dynamic to static” and “static to dynamic” systems. It’s the “static to static” system where a hit is a hit and death is death. Such a system was used in the very early days of the proto-D&D game which was based on Chainmail. Characters simply had “hits to kill” - so instead of having two hit dice, you could take precisely two hits, and then you were dead. For example: "Ogres are killed when they have taken an accumulation of six missile or melee hits in normal combat". As mentioned in the previous post, these “hits” were only later expanded into the more incremental system of hit point rolls and damage rolls, when players complained about dying too quickly. And that’s where hit dice get their name.)

I have always been fascinated by mechanics that add uncertainty at the point of (near-)death. Uncertainty means tension. However, damage rolls are not tense, because they’re routine and average out in the long run. They’re only tense when you’re very low - if you have 6 HP, then the trap’s 2d6 damage roll is the difference between life and death. But up until you get to that threat range, the damage rolls don’t matter, and you might as well just take the average result every time.

"Death spiral" systems, i.e. ones where your fighting capability falls linearly as you take damage, are bad for a different reason. They remove uncertainty up front: whoever gets hit first has probably lost, and the result of a fight is decided and obvious from the beginning..

Essentially, what I have done is extended the relative space of play where a single roll decides the fate of a player character. However, I haven’t made things more lethal overall. In fact, I’ve given players slightly more resources - first they lose their health, and then they get complications, while still having a chance to survive. You could perhaps call it a safety cushion, but the important thing is that the risk is real (unlike, say, 5th edition’s death saves which make it virtually impossible to die). At the same time, I’ve given players more rope to hang themselves with (which is always more fun). In an HP damage system, getting knocked out can be sudden (and double damage critical hits exacerbate the problem), but after it happens there’s nothing players can do about it that. But here, if they’re badly wounded and dicing with death, they always have the option to keep fighting and exploring. If they don’t want to retreat, it’s their own choice.

Compatibility & benefits

D&D with static and ascending damage might look very different to the D&D you know. However, it should be reiterated that this is all entirely compatible with existing materials and modules. When you play a module and it says you take 3d6 damage, you instead take three Wounds. The majority of the time there’s no maths involved in conversion - in fact there’s less maths than when playing normally.

Apart from cutting down on maths and redundant rolling, the Wounds tally system also has a logistical benefit. Character sheets get worn down more from erasing than they do from writing on them. When you play with descending HP, you have to erase a number and write a new one every time you take a hit. When you check a box each time you take a Wound (unlike HP, the maximum number of Wounds is small enough to reasonably be represented as checkboxes on the sheet), you only need to use an eraser when you get healed. And healing is a less frequent occurrence than taking damage. Therefore, you're saving trees by playing this way!

Optional rules

Though these reduce the elegance of the system, I may add them later to tweak the lethality once I see how it works out in playtesting. As always, everything is just theorycrafting so far, unless otherwise stated.

Critical Failures: When you Dice With Death, if you roll exactly your current number of Wounds, you suffer an additional Wound from internal bleeding (and must, therefore, Dice With Death again).

Adrenaline Spike: One exploration turn after any combat or chase in which you have Diced With Death, your adrenaline runs out; you must Dice With Death one more time, unless you have been healed down to your Max Wounds or below.

Static damage & different weapons

• Daggers have a -2 penalty to hit against defenders armed with long weapons. (That means things like swords, spears and polearms.) This does not apply to unaware targets or those who are otherwise unable to defend themselves. 
• Two-handed weapons and crossbows are Devastating. On a natural 20, they deal an additional Wound. Other weapons don't get to do that. 
• Unarmed strikes and improvised weapons (torches, thrown rocks, etc.) only deal damage on a successful Open Doors roll (2+STR in 6).
• Fighters get some other neat bonuses to make up for losing the bigger damage dice - more details on that in a later post.
• Leader monsters and monsters in modules listed with maximum HP may be counted as one HD higher (take 1 Wound more to kill than normal). For example, if a den of goblins (HD 1 = 1 Wound) is lead by a chieftain with 8 HP, then count the chieftain as HD 2 when determining Wounds to kill it.

Bonus: Other potential uses for “roll-between” mechanics

 Notice how when you Dice With Death(tm), you're trying to roll above one target number but below another? Just spitballing, but:

• When you hit with a two-handed axe, if the attack roll is below or equal to your Strength score, you sever a limb.
• When you hit while dual-wielding light weapons, if the attack roll is below or equal to your Dexterity score on your attack roll, you deal double damage.
• When you are parrying with a lighter weapon, if the opponent’s attack roll misses but is above your Strength score, your weapon is flung from your grasp. Otherwise, if the attack roll is below or equal to your Dexterity score, you get a free counterattack.

Making the case for limited ability modifiers in OSR

D&D B/X is, I would wager, the most popular basis for OSR games. Therefore, B/X style ability modifiers are the most common. In case you didn't know, ability modifiers in B/X range from -3 to +3 and are determined like this:

Score	Mod
3	-3
4-5	-2
6-8	-1
9-12	+0
13-15	+1
16-17	+2
18	+3

Nice, unified and symmetric. Except of course when it's not - only positive modifiers affect languages known, and reaction adjustments from Charisma only go from -2 to +2, and ditto for initiative adjustments from Dexterity. But we'll get back to that.

While this is probably the smoothest system in any official edition - more unified than Original and Advanced D&D's jumble of adjustments, and less game-deciding than WotC D&D's gigantic -5 to +5 range, they're not the best choice for everything.

Negative modifiers can be problematic when you want to modify numbers that are naturally quite small. Rulesets will often include things like “you can hold your breath for a number of minutes equal to 1+CON”, which will then require special stipulations and minimums for negative modifiers.

Also, I have witnessed applying modifiers to dice rolls cause headaches to OSR hackers creating their own games using B/X as a starting point (often via Lamentations of the Flame Princess). ‘Esoteric Enterprises’ and other games by Emmy Allen use X-in-6 skills like LotFP, except ability modifiers are applied to skills - though they can never go below 0-in-6 (rolled as a 1-in-36 chance). Since skills start at 1-in-6, this means that a modifier of -3 or -2 is the same as -1, not to mention that a +3 is pretty massive. The WIP post-apoc game Ruinations by Brent Ault has gone through several iterations with its skill system, likewise attempting to include ability modifiers into skills, but trying to dampen their effect. At one iteration of the ruleset, skills were moved up to the d12, starting at 2-in-12, plus ability mods. Once again, anything below a -1 is not accounted for. The skill system was changed in a later version to a d100 where start skills at 20%, and have each point of modifier count for 5%, so a -3 modifier would give a 5% success rate. Which, you'll notice, is mathematically the same as a d20 roll with the modifiers applying in their usual way.

Basically, the d6 skill system is liked (by me and many others) for its chunkiness - adding a pip to a d6 feels much better than adding a handful of points to a d20 - but big modifiers and big chunks don't mix.

I'm going to suggest something to all hackers, tinkerers and homebrewers right now:

Ditch the negative ability modifiers from your game. Completely.

It's okay. Just because you're using B/X as your engine doesn't mean you NEED to have the same ability modifiers. It doesn't break compatibility. You still have the same scores, in the same range of 3-18, for when you take ability damage or whatever. You can still run Keep on the Borderlands even if there isn't some unlucky geezer running around with a -2 DEX. You still have HP, and XP, and AC. You can still use all the great TSR and OSR content out there exactly the same.

Then, squish down the modifier ceiling to one that you think won't break your maths too much.

Yes, it may be somewhat more fun for players to have wide variation in characters' abilities, and amusing to laugh at the one chump with a big negative modifier. But reducing modifiers to a range of, say, +0 to +2, opens up a lot more design space for a homebrewer. Never again will you have to worry about special stipulations when applying modifiers to a base number of 1.

(Btw, this pairs quite well with the static Health/Wounds mechanic I talked about in an earlier post - I'll just have CON modifier increase your starting Health at level 1, but more on that in a later post.)

As for precedents, there are already places where B/X et al. restrict adjustments from abilities to -2 to +2, like reactions, initiative, and XP adjustments - because a +3 would be far too large a modifier on a 2d6 roll, for example. Why not expand these limits to everything, thus truly unifying ability adjustments? A smaller range of ability modifiers that excludes negatives means doing less maths, a larger design space, and fewer special cases.

I propose the following modifiers, and will use them in my next game:

Score	Mod
3-12	+0
13-15	+1
16-18	+2

Essentially, it's the B/X range but with negatives completely removed, and +3 squished into +2. You still have some characters (21.3%) who are very good at a given thing, and a few (4.6%) who are exceptional at it. The rest (74.1%) are just average. And that's okay. Now, your base Bushcraft (or whatever) chance will be either 1-in-6, 2-in-6, or 3-in-6. No special stipulations.

By the way: in the oft-referenced late Gygaxian houserules for OD&D, abilities modify things by +1 or not at all. And they modify very few select things. Constitution of 15 or more gives +1 HP per HD, and so on. In discussions of these rules it is often pointed out that they were made for convention games, and therefore do not represent how Gygax ran the game at home. It is true that many of the changes there improve PC survivability - which makes sense when running a quick convention game. However, the streamlining and restricting the effect of abilities does not necessarily improve PC capability - and in fact set a lower ceiling for it than those in B/X and AD&D. I'm not going to say "if it's good enough for Gygax...", I'm just including it for completeness and to show that it's okay to do things differently to B/X - as long as compatibility is preserved. Compatibility must always be preserved.

Simple OSR Thief skills on a d20

Observation 1: Most of the Thief skills in B/X D&D improve in increments of 5%, which makes using a percentile die rather pointless. You can take the percentile (and x-in-6) Thief skills table, convert all the values onto a d20 target number, and it looks like this (TN rounded up):

Level	Climb Sheer Surfaces	Find/Remove Traps	Hear Noise	Hide In Shadows	Move Silently	Pick Locks	Pick Pockets
1	3	18	14	18	16	17	16
2	3	17	14	17	15	16	15
3	3	16	10	16	14	15	14
4	2	15	10	15	13	14	13
5	2	14	10	14	12	13	12
6	2	12	10	13	11	11	11
7	2	10	7	11	9	9	9
8	2	8	7	9	7	7	7
9	1	6	7	7	5	5	5
10	1	4	7	5	3	3	3
11	1	2	4	3	1	1	1
12	1	1	4	2	1	1	0
13	1	1	4	1	1	1	0
14	1	1	4	1	1	1	0

Observation 2: From this table it is easy to see that most of the skills - Find/Remove Traps, Hide in Shadows, Move Silently, Pick Locks and Pick Pockets - are always within a band of 2 points of each other. Generally, they start at 16-18, improve 1 point per level, before accelerating to a rate of 2 points per level starting at 5th or 6th level. These could very easily be collapsed into one chance without losing much precision - let’s say into the middle chance, Pick Locks, a 17.

One of the remaining two skills, Hear Noise is one that many tables including mine (and some retroclone rulesets) ignore, simply letting players succeed to listen if they spend a bit of time, so it can be ignored here. Climb Sheer Walls is a bit of a tricky one. It’s the only one that starts at a high chance of success, 87%, and improves by one percentage point per level, so it ill fits non-percentile models. However, there is precedent in the OSR of merging Climb into a more “unified” skill system, in LotFP, where Climb improves in steps of the same size as other skills. If Specialists put all their points at 1st level towards Climb, they end up with chances quite similar to the ones in B/X - good chances in climbing (5/6), terrible chances of doing anything else (1/6).

Hacking it

Let’s assume that in our modern mindset we want a resolution mechanic that can be applied not just to Thieves, but all classes, while still retaining Thief superiority. Naturally, we achieve that by treating all other characters as zeroth level Thieves. So, ignoring Climb for a moment, we choose a 17 as our target number at 1st level, increasing by one each level. In other words, to succeed at a Thief skill, you must roll d20 + Thief level for a result of 18 or higher.

Hell, why not call it a nice round easy-to-remember 15, and give Thieves a little boost? The B/X Thief is commonly seen as too inefficient, and in fact AD&D boosts many of the thieving chances by 10%. Now, doing this does improve all characters’ odds from the default 16.6% of LotFP to 30%. But, especially these days, most OSR play takes place in the low levels. I’m okay with letting characters do a bit more. (For comparison, the Mutants & Magic proposal linked above lets 1st-level Thieves succeed on most things on a 12-14+.) Incidentally, choosing 15 as the target number, the new chances start to fall behind the B/X Thief's at 8th-9th level.

"Most LotFP campaigns feature lower level characters, and modern campaigns do not last long enough to build characters to higher levels. ... providing characters more possibilities at lower level and decreasing the importance of gaining levels is important."

- James Raggi, "Playtest Notes" in Eldritch Cock

Now that we’ve moved all skills to this mechanic, the obvious next step is other “common activities” with X-in-6 odds like Foraging, which LotFP turns into the Bushcraft skill, and Open Doors, which is not a skill but an X-in-6 chance modified by Strength. Open Doors should certainly be modified by Strength in our new system too. One benefit of moving to the d20 is that if you want ability scores to affect the odds of skills, you can, simply by adding the ability modifier to the roll. Wisdom would be used for Bushcraft, Dexterity for Stealth, Intelligence for Tinker, and so on. The modifiers have a bit of an impact but do not overflow the die size. Also, we are now rolling high (like all other rolls), instead of rolling low on a d6 or percentile, if you care about that sort of unification/elegance nonsense. (I don't think the d6 is bad at all, personally, in fact I really like how chunky the increments feel.)

Finally, let’s get suspiciously modern and use the term “proficiency” for adding Thief levels to the roll. Thieves shall have proficiency in Stealth, Climb, and Tinker. If we take a leaf from LotFP’s increasing demihuman skills, then Dwarves would have proficiency with Architecture, Elves with Search, and Halflings with Bushcraft (and also have a +10 to hide in the wilderness). I would also probably give Fighters proficiency in Open Doors, because why not? They’re likely to be the most physical type.

A summary of the skill system

All activities and skills (Climbing Sheer Walls, Finding Traps, Removing Traps, Hearing Noise, Hiding in Shadows, Moving Silently, Opening Locks, Picking Pockets, Forcing Open Doors) are rolled on a d20. The appropriate ability modifier is added, as well as Thief level if the activity is thiefy. A result of 15+ is a success.

Skills/activities:

• Architecture: INT, +Dwarf level
• Bushcraft: WIS, +Halfling level
• Climb: STR, +Thief level
• Languages, Medicine: INT
• Open Doors: STR, +Fighter level
• Search: INT, +Elf level
• Stealth, Sleight of Hand: DEX, +Thief level (these skills can be rolled into one)
• Tinker: INT, +Thief level

(Sneak attack is no longer a skill, but a simple 2x multiplier, possibly increasing with Thief level.)

Now that all Thief activities progress the same, you can combine those that use the same ability, i.e. Stealth and Sleight of Hand. If you see Tinker (Pick/Remove Traps) as an activity requiring more dexterity than intelligence, then that can be merged in too for a general "Thievery" skill. As an extension of the system, you could have character backgrounds that give you background skills granting a +2 bonus to certain activities.

Pros & Cons

So what’s the score? We have made abilities slightly more important, which depending on your taste may be a good thing or a bad thing (but actually less important compared to roll-under ability checks). We now have a Thief and not a Specialist - we’ve removed “builds”, option paralysis, customization - which again you may see as either good or bad. We've made Thieves decent at everything, but far worse at climbing (I dunno, give them a +10 to climb or something if you want). As a positive, we’ve reduced the space taken up by skills on the character sheet, since you no longer need to list the individual skill levels, only whether you’re proficient in them - adding your level to the roll is easy enough. And there's no need to print a Thief skills table in the rulebook anymore.

However, I see some serious risks in going in this direction. Those risks are psychological shifts that may happen in dungeon masters when moving from a “X in Y” chance to a target number which has treacherous resemblance to the modern “d20 + proficiency vs. difficulty class” mechanic of 5e. The danger is that DMs will start to see the fixed target number of 15 as a "default DC" that they will begin to carelessly modify. They may be tempted to do this where they would not have been in a d6 skill system. LotFP's rules only mention modification of the chances in two places: opening giant stone doors, and attempting to forage in different terrains such as the desert. Modifying the target numbers too often may give rise to a treadmill where characters get more competent but DMs constantly raise the obstacles in response. Because... for some reason a locked chest in a high-level dungeon would have a higher DC to open? I am generally against that, and it should be used very sparingly, as LotFP does. Just let players know their chances of success, and let characters feel competent! This psychological risk of treadmills could perhaps be mitigated by pre-applying the modifiers and listing the naked die result required on the character sheet, as saving throws are handled, though that would take up a bit more space on the sheet and require updating every level.

The other risk is that it will tempt DMs to call for knowledge rolls, and perception rolls. Those are harmful too, but the explanation why is a subject for another blog.

Finally, I'd like to say that I'm not under the impression any of this is an original idea. The Thief seems to be one of those topics of eternal discussion. In fact I'm almost certain there are already several blogposts with same idea, but Google failed to find me any so I'm barfing my notes on here.