Last Updated: 1/28/2022

I make no claim of originality for many of the house rules that follow, and I have freely adopted the ideas of many others. I have acknowledged sources for some of the house rules when I can remember where I got an idea from. Please contact me if you see a house rule you feel needs to be credited. Whether credited or not, I remain grateful to all of the players who have contributed their wonderful ideas over the years. Peace.

I should also note that I’m always tweaking my games; therefore, my house rules are constantly changing. What follows are the house rules that were used for my last B/X game that concluded in September of 2021. Tentative house rules that are still being tested by my players are not listed. Based on my last B/X game, these rules will be updated based on actual play should I ever run another B/X game.

Abbreviations

  • H            Dungeons & Dragons, The Basic Set, Holmes (1977, an introductory presentation of original D&D)
  • B            Dungeons & Dragons, The Basic Set, Moldvay (1981 revision of Holmes)
  • X            Dungeons & Dragons, The Expert Set, Cook (1981, continuation of Moldvay’s revision for upper levels)
  • RC          Rules Cyclopedia (1991, compilation of Mentzer’s 1983 revisions of Moldvay)

Example: B5 refers to Moldvay’s ‘B’asic book, page 5. Whenever I refer to “standard” rules, I am referring to the B/X books.

Character Creation (B5-6)

  • All 1st level characters begin with maximum Hit Points.

Bonuses and Penalties Due to Abilities (B7)

  • Intelligence: For magic-users & elves only.
    • 13-15 INT grants +1 Known 1st-Level Spell
    • 16-17 INT grants +2 Known 1st-Level Spells
    • 18 INT grants +3 Known 1st-Level Spells
      • These known spells are in addition to the standard one known spell that magic-users/elves begin play with in the standard rules. These spells are in the characters spell book. (Note: 1st-level magic-users & elves still can only “memorize” one spell at a time, but they may now have a greater selection to choose from at first level.)
  • Dexterity: For thieves only.
    • 13-15 DEX grants +5% to base thieving ability scores (+1% to Climb Sheer Surfaces)
    • 16 DEX grants +10% to base thieving ability scores (+2% to Climb Sheer Surfaces)
    • 18 DEX grants +15% to base thieving ability scores (+3% to Climb Sheer Surfaces).

Clerics (B9)

  • Clerics are not restricted to “non-edged weapons,” although they are still restricted to specific weapons as determined by their religious order (e.g., they can use a sword, or any other weapon that is permitted by their order or deity/deities). See Weapon Use & Damage below.

Dwarves & Elves (B9)

  • Neither dwarves nor elves possess infravision. See their respective Class Variant Handouts.
  • For elves and magic house rules, see Magic-users & Magic below.

Magic-users (& Elves w/ regard to starting spells)

  • 1st-level magic-users and elves begin play with 1 known spell plus 1-3 additional known spells depending on the character’s INT bonus (see Bonuses and Penalties Due to Abilities above).
    • Players selecting either of these classes may pick the 1 standard known spell (B16-18); however, any bonus spells due to INT will be randomly determined. (Note: It is strongly recommended that players select Read Magic since without this spell any discovered spell books or scrolls cannot be read, and scrolls are one of the few ways to cast spells without the restriction of “memorization.”)
  • While still restricted in terms of weapon use and damage, magic-users are not restricted to only using daggers (B10). See Weapon Use & Damage below.
  • Regarding armor usage and Magic-users, see Armor, Armor Class, & Shields below.
  • For Magic-users and Magic house rules, see Magic below.

Fighters

  • Chop when they Drop: As the class that is dedicated to mastering martial skills, anytime a fighter kills an opponent, they immediately gain a free attack on any other enemy within reach. Should they slay that opponent as well, they gain another free attack on a nearby enemy. These attacks continue until the fighter either misses, fails to kill an opponent, or runs out of enemies within the reach of his weapon.
    • Credit: I took this house rule from John Arendt’s blog, Dreams in the Lich House. However, the rule reportedly goes back to Dave Arneson.

Thieves

  • Thieves receive a bonus to the base percentage of all thieving abilities except Hear Noises based on their DEX-score ability bonus (see the above Bonuses and Penalties Due to Abilities house rule). The DM may also apply additional modifiers to these abilities depending on the situation. (Note: Players are encouraged to review the additional Handout on how thieving abilities are interpreted and used in the context of this retro-styled game.)

Weapon Use & Damage

  • There are no specific weapon restrictions for most character classes (e.g., a cleric may use a sword if permitted by their order, and a magic-user may opt to use a weapon besides a dagger).
  • In order to avoid eliminating the advantages of the fighter, weapon damage will be determined by class (e.g., martial skill of the class, size of class, etc.) and weapon category according to the following Weapon Damage Chart:
ClassSmall WeaponsMedium WeaponsLarge Weapons
Fighter, Elf1d61d81d10
Cleric, Dwarf1d41d61d8
Halfling*1d41d61d6
Thief1d61d61d6
Magic-User1d41d4*1d6**
Weapon Damage Chart

Small Weapons: any small, light weapon…a dagger, a sling, a cudgel, a roll of coins, etc. A character using a small weapon in melee will always loses Initiative to an aware, unsurprised enemy with a larger weapon in the 1st round of combat, and continues to strike last until scoring a successful “hit.” This reflects the advantage of range.

Medium Weapons: bows, broadswords, crossbows, flails, hand axes, javelins, maces, spears, war hammers, quarterstaffs (two-handed), long swords, etc.

Large Weapons: battleaxes (two-handed), great swords (two-handed), various types of polearms (two-handed), lances (mounted only), etc. A 2-handed weapon always strikes first in the 1st round of melee against an opponent with a 1-handed or smaller weapon; on all subsequent rounds the wielder of the 2-handed weapon will strike LAST IF the opponent with the smaller weapon scored a “hit.”

  • * Halflings inflict 1d6 damage when using a sling.
  • * Magic-users do 1d6 damage when wielding quarterstaffs with two hands.
  • ** Magic-users have a -1 penalty to hit when using large weapons.

Credits: This is a slightly modified take on the house rules presented on blogs like Akratic Wizardry and B/X Blackrazor.

  • Thrown weapons do receive the character’s STR bonus (as per RC 103).

Fighting Options

  • Two-Weapon Fighting: With the exception of clerics and magic-users, characters with 13+ Dexterity may use a smaller one-handed weapon in their off-hand. If the character fights defensively, the off-hand weapon provides a +1 bonus to AC just as a shield (this bonus stacks with the other Fighting Defensively bonuses discussed below); if the character attacks as normal they may roll the damage die TWICE on a successful attack roll and pick the higher of the two rolls. A character may only attack or fight defensively in a round, not both.
  • Pressed Attacks: At the cost of making themselves more vulnerable to attack, Fighters (and Fighters only) may press an attack: +2 Attack Bonus (AB) / -4 AC penalty. This maneuver must be declared prior to determining Initiative.
  • Fighting Defensively: All classes may elect to spend an entire combat round fighting defensively (parrying, blocking, dodging, feinting, etc.). Characters fighting defensively may not attack at all during the round and receive +2 AC bonus (+4 AC bonus for Fighters only). This option may be used with the standard Fighting Withdrawal rule (B25). Fighting defensively must be declared prior to determining Initiative.
  • Readied Bows: Players whose characters have readied bows/crossbows (AND have NOT been surprised) may fire immediately after initiative, and prior to movement, regardless of which side won initiative. This does not apply to thrown ranged weapons like slings or hand axes.
  • Switching Weapons: Changing to another accessible weapon in combat incurs a -2 attack penalty (e.g., dropping a weapon and drawing a new weapon).
  • Attacking from Behind: Unaware targets attacked from behind grant the attacker a +2 AB. (Reminder: per the standard rules, thieves gain +4 to hit and damage dealt is doubled.)
  • Mounted Attack Bonus: Mounted attacks (except with small/short weapons like a dagger) receive a +1 AB against foes on foot (unless the foe is some kind of Huge/Gigantic monster).
  • There are many other possible modifiers that may be applicable in combat, and such modifiers will be discussed as they arise during play (e.g., attempting to fight with a large two-handed sword in a cramped tunnel underground might incur an attack penalty.)

Armor, Armor Class, & Shields

  • Classed-Based Armor Restrictions: Players can use any armor, regardless of class. However, there will be penalties for some classes wearing certain types of armor.
    • Thieves must be unencumbered and cannot use any armor heavier than leather in order to use certain class-based abilities like thieving skills.
    • Magic-users cannot cast spells while wearing any armor or using a shield.
  • Bows & Heavy Armor: Characters cannot effectively use bows in heavy armor (e.g., plate armor), and cannot use bows at all while mounted and wearing plate.
  • Touch & Throw Attacks: Only apply Dex-based AC bonuses when the target of a touch attack or when targeted by thrown oil/holy water (i.e., bonuses from armor are of no use in such situations since the attacker is not attempting to penetrate armor).

Encumbrance

  • Note: I am retaining the somewhat clunky coin-based encumbrance system (B20), not because it is precise or even realistic, but because it serves to reinforce the core motivation of the game: adventure to acquire treasure. It also forces players to make interesting decisions. For example, if a player, or group of adventures, cannot carry that last pile of 500 gold out of the dungeon (also worth 500 experience by the way) without being over-encumbered, then perhaps they might be willing to remove, and leave behind, the fighter’s suit of plate armor (that weighs the equivalent of 500 coins, see B20)? If so, the adventurers now have to risk making it to a safe place with that gold since their fighter has left behind his/her armor. Better have the cleric pray for unsuccessful wandering monster checks.
  • As in the Holmes’ presentation of OD&D, players should note the location of items being carried in order to help them envision their load. Here is the excerpt from Holmes (H7):

In order to give players a better idea of just how encumbered they are by equipment and subsequent additions of treasure to their load, it is suggested that they note on a sheet of paper just where or how each item they have with them is stored or carried. Example: The magic-user, Malchor, is about to set off on a dungeon exploring expedition. In addition to his normal garb of boots, loin cloth, robe, girdle, and pointy hat he notes that he is bringing the following equipment with him:

  • 2 daggers (1 in girdle, other in boot)
  • 1 back pack
  • 1 large sack (in pack)
  • 1 — 50′ coil of rope (in pack)
  • 1 standard rations (in pack)
  • 1 small sack (in pack)
  • 12 iron spikes (in small sack in pack)
  • 1 quart wine (in pack)
  • 1 small sack, shoulder slung, left side
  • 2 flasks of oil (shoulder sack)
  • 2 vials holy water (shoulder sack)
  • 1 garlic bud (shoulder sack)
  • 1 wolvesbane bunch (shoulder sack)
  • 20 gold pieces (in purse hidden under robe)
  • 1 water skin, shoulder slung, right side
  • 1 tinder box (tucked in girdle)
  • 1 lantern, filled with oil (left hand)
  • 1 — 10′ pole (right hand)

Open Doors

  • In addition to STR bonus, characters using a crowbar on typical doors add +1 to the Open Doors roll.
  • Each additional person trying to open a door adds +1 to roll; however, usually only two people can work together on most standard-sized doors.
  • Breaking down a door prompts an automatic Wandering Monsters check.

Magic

  • In addition to the standard (and rarer) spell research (X51), new spells for magic-users and elves (NOT clerics) are acquired via the following methods:
    • finding new spells through adventuring. For example, discovering a tome of spells in an unearthed crypt. (Note: this is one of the primary reasons for young magic-users to go adventuring.)
    • acquiring new spells from another magic-user’s own collection, or under another magic-user’s tutelage. (Note, however, magic is jealously guarded in this game, and players should expect NPC magic-user’s to try and extract a high price for such knowledge, whether in actual coin, through servitude, or in return for a favor or the completion of a task.)
    • Reminder: per standard B/X rules, the content of magical scrolls cannot be transferred to a player’s spell book. In short, these spell scrolls do not actually contain the magical formulae needed to know how to cast a spell. They represent spells that have already been prepared in a way so as to be cast by other individuals without the need for ritual preparations (i.e., “memorizing”)
  • The spell slots available to magic-users and elves, only pertain to the maximum number of spells that may be ritually prepared/memorized.  The slots do not represent the number of actual spells that a magic-user or elf may have in their spell book(s). In short, ignore the comments about the number of spells in a spell book on page B16.
  • Magic-users do not need to wait until name level (i.e., level 9) to create potions or scrolls (as per X51), although creating certain potions/scrolls will certainly require a higher level (e.g., 1st level magic-users cannot create scrolls containing 3rd level spells).  All magic-users are also alchemists. As such, all a magic-user requires for a potion is a recipe, a laboratory (portable or permanent), and ingredients (expressed in actual rare ingredients that must be acquired or a simple monetary cost).
    • Alchemical recipes are found in the same collections of arcane lore (i.e., spell books) that spells are; and therefore, they are just as carefully (and jealously) guarded as the spells.
    • Players will be notified if such “books” contain any recipes during play.
    • Rules for scroll creation remain the same as indicated on page X51, although the level restriction has been lifted.