I'll skip huge swaths and just focus on the most interesting bits. If you have never read B/X, I'd recommend taking a look for yourself (for the reasons explained here).
Here we go!
B1 - credits and art, skipped.
B2 - Foreword and acknowledgements.
My house rules (and this series of posts, of course), are meant for people with a background in D&D, so I will not teach how to roleplay. But, like B/X, they are based on problems that emerged from my real experiences with the rules, and I should probably start my own foreword with that.
B3 - How To Use This Book, Definitions of Standard D&D Terms.
One thing to note is that the wilderness is too deadly for 1st-level PCs and becomes too easy around 8th level, which also needs to be taken into account.
B4 - "At the start of the game, the players enter the dungeon..." interesting advice and probably too often ignored. The "caller" is explained here but I don't use it my games.
Use of the Word "Level" explains the confusion created by the lack of a good thesaurus when the word "level" was used in the game, since characters, dungeons, spells, and monsters are all divided into levels that are not necessarily compatible (e.g., a level 5 MU can get a level 3 spell in dungeon level 4). Later editions dropped monster levels, but it's the use that makes the most sense when compared to PC levels ("A monster's level is equal to the number of Hit Dice").
I'll skip "How to Use Dice," but the section below is interesting because it never really explains how to win or what the game's actual goals are, beyond the obvious goal of having fun. Not great, IMO, but I'll skip this is my game too.
This section explains the creation of PCs. Not much to add here; I find 3d6 in order too harsh (and not even used in the basic modules anyway), equipping characters too boring (it could be replaced by starting packages, which I'll leave as an option), and the rest can be simplified. See my version below.
B6: Character Abilities, Ability Score Adjustments, Hit Points and Hit Dice: nothing to comment here.
It is interesting that Charisma and Constitution cannot be changed, as they are useful to all PCs. But, to be honest, I wouldn't see a problem with reducing them to 9 to raise prerequisites. However, I find the whole idea of prerequisites an unnecessary complication, so I'm skipping it.
1st-level HP is a problem that is often house-ruled away because most players do not want PCs starting the game with 1 HP. But since I don't treat 0 HP as immediate death in my games, I won't change it.
I love the simple -3 to +3 bonuses and penalties, so I'll probably keep them. I'm replacing the maximum number of retainers and morale with something else, and since there is no separate magic save for now, Wisdom and Charisma will grant additional languages like Intelligence does.
Still, every ability score matters, since I'll be using a roll-under system for skills.
B8: Character Class Tables
One of my main reasons for creating my minimalist version of B/X is that I dislike looking up tables. I'd much rather have a 7th-level fighter gain a +7 attack bonus and +7 to saving throws. It works surprisingly well, being essentially Target 20 with a few twists of my own.
Thief abilities are described here. I've turned them into skills because that solves several problems. Skills are based on ability score minus 10 (minimum 0), plus level, giving starting thieves roughly a 15%-20% chance of success, which I find reasonable.
Backstab is NOT described here, and I won't be turning it into a skill. It will remain a special ability.
1. Introduction
This is a minimalist version of classic/OSR games. It functions as a toolbox, not a complete game. It has no spells or monsters, for example; it only replaces character rules.
This game assumes:
• You are familiar with classic/OSR games.
• You are looking for a quicker, easier version (or reference book) that still fits perfectly, with little conversion needed.
• You want more options with less complexity.
• You want to keep the d20, six abilities, saving throws and other traits of the classic games.
In short, this game has:
• A single d20 mechanic. To do almost anything, roll 1d20 plus ability bonus/penalty and other modifiers, try to hit a DC (usually 20).
• Attack rolls use a similar system, adding attack bonus (AB) and hitting the target's AC.
• A single saving throw, although some classes and races will have certain bonuses. To make a saving throw, roll 1d20, add your level and any appropriate bonuses. The DC is usually 20, but see "miscellaneous rules".
• Ability checks work in a similar manner. "Roll under" is optional and not assumed.
• Spell slots and Vancian casting are replaced by a similar check.
• Ability scores have some additional functions.
• Identical XP tables for all classes. You can replace XP with "milestones" or some other form of advancement if desired.
• No prime requisites. No XP bonuses due to high ability scores, etc.
• Four classes, four races. Race is separated from class. Any race can pick any class, barring setting limitations.
• No level and class limitations for elves, dwarves, etc. Some aspects of these races have been changed to compensate.
• Fewer armor/weapon limitations. These have been reduced to a minimum.
• Streamlined skills and checks. Percentage skills, 1-in-6 checks, etc. are replaced by a d20 roll, which includes thieves' skills.
• Advantage/disadvantage is optional. Advantage means you roll two dice and pick the best one; disadvantage means the opposite. This replaces +4/-4 modifiers if you dislike these (or if passing/failing a check would be impossible and you want to make it possible).
• Fighters, experts and mages replace other terms (fighting-man, magic-user, etc.) for short.
• Minimal added crunch (note to self). Document must be 60 pages or less (including rules on PCs, monsters and GMs). Appendixes with more options (but avoiding new mechanics) are permitted.
The Basics
When a character tries to do anything that carries a risk of failure, roll 1d20, add your modifiers (usually a skill), with 20 or more signifying success. A "hard" difficulty is assumed; the GM may set other difficulty numbers (DC) for particularly easy or hard tasks, as indicated in the table below.
Notice that a DC of 18 is similar to 1-in-6 chances or a 15% chance, making it easy to convert tasks from other systems to this one (e.g., if you have 3-in-6 chances of getting lost, avoiding it is an "easy" check).
Natural 1
A natural 1 is an automatic failure and, when attempting something risky, means potential disaster (DM's call). Roll again, with a success meaning you barely avoided disaster (but still failed to reach your goal and might suffer a small setback defined by the GM).
The table below provides suggested Difficulty Classes (DCs) for common tasks.
| Difficulty | DC | % Chance | Equivalent |
|---|---|---|---|
| Very Easy | 8 | 65% | ~4-in-6 |
| Easy | 11 | 50% | ~3-in-6 |
| Medium | 14 | 35% | ~2-in-6 |
| Challenging | 18 | 15% | ~1-in-6 |
| Hard | 20 | 5% | — |
| Very Hard | 25 | — | — |
| Nearly Impossible | 30 | — | — |
| Epic | 35 | — | — |
| The Stuff of Legend | 40 | — | — |
A failure after rolling a natural 1 is called a mishap.
For example, when you are climbing, rolling a natural 1 means you risk a mishap, such as falling halfway through. This does not usually apply to attack rolls.
Natural 20
A natural 20 may mean a special success or critical hit, depending on the GM and the circumstances.
In combat, I treat a natural 20 as an automatic hit, with maximum damage (e.g., 9 instead of 1d6+3).
Saves and Magic
Optionally, the GM may rule that a natural 20 and natural 1 have similar results for saving throws and magic rolls.
Trying Again
You can usually try again, depending on the consequences of your failure.
Even if a natural 1 caused you to break your lock picks, you can try again if you have a second set, etc. This requires time, and some rolls can only be attempted once a turn, once a day, etc.
Everything Else
Use your favorite game as written, adapting to d20 when necessary.
2. Player Characters
How To Create A Player Character
There are seven steps to create a player character, using an "AABCDEF method" for easy memorization.
A starting character can be a blank slate, shaped entirely by adventure. Backstories are welcome, but what defines your character is what they do, not past glories.
Every character needs a reason to adventure and to keep adventuring. If that reason is lost, find a new one, or retire the character and create another.
• Abilities. Roll 3d6 six times to find out your character's abilities. Roll in order or assign to taste. If the sum of all abilities is 60 or less, you can discard and roll again. Alternatively, assign either 14, 12, 11, 10, 9 and 7, or 13, 12, 11, 10, 9 and 8 to your ability scores.
• Ancestry. Choose an ancestry. This will affect your ability scores.
• Bonuses. Check the Bonuses and Penalties table and record any modifiers tied to outstanding ability scores.
• Class. Pick a class. This determines your HP, attack rolls, saving throws, and any special abilities. Note all of these down.
• Details. All characters start at 1st level with 0 XP. Record both on your sheet. Pick any additional languages and skills you can.
• Equipment. Every character starts with 3d6×10 gp. Browse the Equipment and Weapons table and outfit your character within your budget, writing down your purchases and any money left. Record your Armor Class (AC) based on whatever armor you chose.
• Finishing Touches. Choose an alignment, write down any physical details or background you find appropriate, and give your character a name. Don't get too attached.
Abilities
Each ability score tells you something different about your character:
• Strength measures raw muscle power and physical force. Characters with high Strength are better suited to the fighter class.
• Intelligence reflects the capacity to learn, retain knowledge, and solve problems. High Intelligence favors the mage class.
• Wisdom represents intuition, common sense, and sound judgment. High Wisdom suits the cleric class well.
• Dexterity captures speed, agility, and fine motor control. A character with high Dexterity excels in the thief class.
• Constitution combines overall health and endurance. It influences every class by potentially modifying the number of hit points a character has.
• Charisma is a blend of appearance, personal magnetism, and leadership. It shapes how monsters and NPCs react to the character.
Ancestries
There are four ancestries: Dwarf, Elf, Halfling, and Human.
1. Dwarf
A sturdy and enduring folk, renowned for their skill in mining, smithing, and stonework. They are typically stout in build, about 4' tall, long-lived, and known for their stubbornness and loyalty.
• +1 to Strength or Constitution (random).
• Favored weapon (+1): axes, maces, and crossbows.
• Darkvision 60'.
• Bonus: +4 to the Find skill to detect structural abnormalities (hidden passages, moving walls, built-in traps, recent changes, etc.).
• +2 to all saving throws.
• Limitation: cannot use great weapons and must use two hands for large (1d8) weapons such as a longsword.
2. Elf
Elves are an ancient and graceful people, attuned to magic and the natural world. They are almost as tall as humans but thinner. They are long-lived to the point of near-immortality and carry themselves with an otherworldly air that other races often find either enchanting or unsettling.
• +1 to Intelligence or Dexterity (random).
• Favored weapon (+1): swords and bows.
• Bonus: +4 to the Find skill to detect hidden doors. +4 to the Hear skill.
• Darkvision 60'.
3. Halfling
Halflings are a small and nimble folk, cheerful by nature and surprisingly hardy for their size (about 3'). They have a reputation for going unnoticed when they wish to, and for a love of comfort, food, and the occasional unexpected adventure.
• +1 to Constitution or Dexterity (random).
• Favored weapon (+1): all ranged weapons.
• Bonus: +4 to the Stealth skill.
• +2 AC against attacks from large creatures (larger than human-sized).
• +2 to all saving throws.
• Limitation: cannot use great weapons and must use two hands for large (1d8) weapons such as a longsword.
4. Human
Humans are the most widespread and adaptable of peoples, found in every corner of the world and in every walk of life. What they lack in the innate gifts of other ancestries they make up for in ambition, versatility, and sheer variety.
• +1 to three random different ability scores.
• Favored weapon (+1): choose two of swords, axes, maces, spears, small weapons, bows, crossbows, slings, etc. Alternatively, choose a bonus language.
• Bonus skill: choose one skill.
Bonuses and Penalties
Each ability score has a corresponding bonus or penalty.
| Score | Adjustment |
|---|---|
| 3 | -3 |
| 4-5 | -2 |
| 6-8 | -1 |
| 9-12 | No adjustment |
| 13-15 | +1 |
| 16-17 | +2 |
| 18 | +3 |
| 19* | +4 |
| 20* | +5 |
Strength adjustments apply to melee attack and damage rolls.
Dexterity adjustments apply to ranged attack rolls and Armor Class.
Constitution adjustments apply to hit points gained per hit die.
Intelligence, Wisdom, and Charisma adjustments grant additional languages. For example, if your adjustments are -1, +3, and +2, you gain four additional languages (minimum zero).
Level 1 characters cannot start with an ability score above 18. If an ability reaches 19 during character creation, lower it to 18 and add 1 point to another random ability.
Classes
There are four basic classes: Cleric, Expert, Fighter, and Mage.
The Expert replaces the traditional Thief; while his default skills lean toward thievery, he may trade them for others.
When choosing a class, look at your highest abilities and consider which classes they favor. A score of 13 or above in a relevant ability is a good indicator.
As a rule of thumb:
- Strength favors Fighters.
- Dexterity favors Experts.
- Intelligence favors Mages.
- Wisdom favors Clerics.
1. Cleric
With the power granted by your deity, you protect the innocent and weak from the forces of darkness, fight against the dying of the light, and smite the wicked creatures that roam the earth.
Class Features
- HD: 1d6
- Attack Bonus: level / 2 (round down)
- Saving Throw: level + 2
- Spellcasting: level / 2, round down (see the Magic chapter)
Turn Undead
Clerics can repel or destroy undead by brandishing their holy symbol.
The undead must be visible and within a 60-foot radius of the cleric.
Turning can be attempted once per minute, in lieu of an attack.
Turned undead flee by any means available and will not harm or contact the cleric for one minute.
To turn undead:
- Roll 1d6.
- Add the cleric's level.
- Subtract the target's HD (for example, 2 for zombies).
A result of 5+ succeeds.
A result of 10+ destroys the undead permanently.
The roll result also indicates the total HD of undead affected (minimum one creature, maximum 10 HD).
Examples:
- A result of 11 against zombies destroys 5 zombies.
- A result of 11 against skeletons destroys 10 skeletons.
In mixed groups, lower-HD undead are affected first.
Taboo
A cleric must use blunt weapons and cannot use edged weapons (including swords, bows, spears, etc.).
A cleric who breaks this or other taboos appropriate to their alignment or deity may lose supernatural powers until atonement is made. Specific consequences depend on the setting.
2. Expert
Your shadowy past no longer matters. You chose a life of adventure, and the skills you developed will come in handy.
Class Features
- HD: 1d6
- Attack Bonus: level / 2 (round down)
- Saving Throw: level + 2
Skilled
You gain seven bonus skills:
- Athletics
- Decipher
- Hear
- Find
- Locks & Traps
- Pick Pockets
- Stealth
(See Skills below.)
Backstab
When backstabbing (see the Combat chapter), you may use your backstab bonus instead of your combat bonus.
In addition, add your level to any damage dealt with a successful backstab.
3. Fighter
You might call yourself a knight, barbarian warrior, soldier, or ranger, but it makes no difference. Your main skill is violence, a useful talent in this perilous world.
Class Features
- HD: 1d8
- Attack Bonus: level
- Saving Throw: level + 3
Cleave
When you reduce an opponent to 0 HP with a melee attack, you may immediately make an additional attack against another opponent within range.
The maximum number of attacks gained this way is equal to your level.
Extra Attack
Fighters gain:
| Level | Attacks |
|---|---|
| 7 | 3/2 attacks |
| 15 | 2 attacks |
| 20 | 3 attacks |
3/2 attacks means you attack twice in the first round, once in the second, twice in the third, and so on.
4. Mage
Common folk fear you because you dare to cross the boundaries of morality and superstition.
When adventurers descend into the abyss of ancient ruins, you are the one who knows what lurks below.
Class Features
- HD: 1d4
- Attack Bonus: level / 2 (round down)
- Saving Throw: level + 1
- Spellcasting: level / 1, round down (see the Magic chapter)
Taboo
A mage cannot cast spells while wearing armor or using a shield, as these interfere with the flow of mystical energies.
Additionally, a mage requires one free hand to cast spells.
A two-handed weapon does not prevent spellcasting, since it may be momentarily held in one hand while casting.
