I’m not a huge fan of having lots of ‘house rules’ (although I was once); and I think the beauty of D&D B/X (and similar editions of that era, and the newer OSE, etc) is the malleability of the rules and play (vs. the heavily structured and detailed approach of 5E with very rigid processes) that allow many things to be resolved ‘on the fly’ on a case by case basis and therefore don’t require documented ‘house rules’. But a few key items are worth formally recording for regular ongoing use.

Going forward these are the current draft set of house rules I plan to adopt for future B/X-OSE D&D games, I’ll call then version 0.9 as they are an initial collection of thoughts. In the future as I use them and/or add or remove items I may post periodic updates, and will update the version number appropriately. I’ve added to my existing thoughts and also picked up new ideas from other people’s thoughts on this subject so have added some links to material and other people’s ideas on house rules at the end.

Hit Points

• At Character Creation all 1st Level Characters begin with maximum hit points (+ any CON bonus).
• On reaching 2nd Level Characters make a modified (favourable) roll for hit points as follows:
  • Fighters & Dwarves: d4+4 so they receive 5-8hp (+ any CON bonus).
  • Cleric, Elves & Halflings: d3+3 so they receive 4-6hp (+ any CON bonus).
  • Magic-Users & Thieves: d2+2 so they receive 3-4hp (+ any CON bonus).
• On reaching 3rd Level hit points are rolled as usual with the normal die*

* A part of me actually favours the ‘just give PCs the maximum hit points at every level‘ concept, on the grounds they are adventurers, and therefore somewhat exceptional, or at least above average – but this might detract a little from the flavour of old school D&D by the time the characters are in the 4th to 7th level range and the whole feel of the danger and the risk involved in adventuring may be reduced. However everything is relative and a DM could easily accommodate this by making some encounters that little bit tougher or larger (e.g. a group of 10 orcs instead of 8) to offset the maxed out hit points, while the players will gain solace from having the seemingly high hp regardless – food for thought at least.

Fighters Chop When They Drop

Anytime a fighter kills an opponent (in hand-to-hand), they immediately gain a free attack on any other enemy within reach of their weapon (typically 5′). Should they slay that opponent as well, they gain another free attack on another 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. This provides the Fighter class (specifically) with some martial benefit from their dedication to combat skills and weapon expertise that is otherwise not represented in any way in B/X. It does not apply for Dwarves, Halflings or Elves. This rule reportedly goes right back to Dave Arneson.

I picked up this rule from the Rambling Cleric and John Arendt’s Dreams in the Lich House blogs.

Magic-User Weapons

A Magic-User can use a Dagger, Club or a Staff as a weapon (and if need arises, a Torch).

Magic-User & Elf Known Spells (Spell Books) at 1st Level

Magic-Users and Elves* gain additional bonus 1st Level spells in their starting out spell book based on their INT bonus (as per the usual bonus table – see below) – these bonus spells are determined randomly (i.e. the player chooses his or her base known spell as per the rules, then rolls randomly from the remaining 1st level list for the bonus spells gained from above-average intelligence):

• INT 13-15: +1 known 1st level spell in spell book.
• INT 16-17: +2 known 1st level spells in spell book.
• INT 18: +3 known 1st level spells in spell book.

* As an aside I am currently mulling with the idea that Elves have a more innate style of spell casting, so that while they still operate the same as magic-users, and would still get the known spell bonus above, they just ‘know’ the spells in their list of known spells and don’t have or need a physical ‘spell book’ to store them. There have been some interesting thoughts on this by other old school gamers.

Magic-User Extra Spell Slot(s) from Familiar or Artifact

This applies only to Magic-Users and not to Elves. Starting from 1st Level when the PC is first created a Magic-User may choose either to have a small familiar or an artifact gained during training; and that provides a bonus to their spell casting. Benefits are:

• Familiar (Small Normal Animal)
• Is a normal non-fantastical creature such as a Bat, Cat, Owl, Rabbit, Rat, Raven, small Snake.
• It communicates with the magic-user through empathy (the mental sharing of emotions & feelings), and can understand simple verbal or mental commands received from the magic-user.
  • Familiar has 1hp for each level of the Magic-User (and always counts as a 1HD Creature).
  • Familiar is AC 4 and only ever fights in self-defence (inflicting 1-3 damage).
  • If killed the Familiar disappears in a puff of smoke/gas, and the Magic-User suffers the shock causing them to fall unconscious for 1d6 + ½ the magic-user’s level (rounded down) rounds. Treat as similar to a Sleep spell effect but that can affect a magic-user of any level.
  • The familiar can be ‘resummoned’ 24-hours after being ‘killed’ by the Magic-User taking 1 hour of effort to do so and costing 1gp/level of the magic-user for necessary materials/enticements. The resummoned familiar is always the same one as previous.
• If the Familiar is alive and within communication distance* of the Magic-User the latter gains 1 additional spell slot to memorise a spell (this can be any level of spell the magic-user is eligible to use). This slot or memorised spell is lost as soon as the familiar is killed or passes out of communication distance – an empty slot will become available to the character once the familiar is back in range and alive. The spell must be memorised as normal (i.e. over night).
• If the Familiar is alive and within communication distance* of the Magic-User the latter can temporarily enter a trance and see and hear through their familiar – but while doing this they are blind and deaf to their own surroundings (so can easily be sneaked up on to be backstabbed, etc).
• The DM should add any additional info needed (such as familiar movement speed).

• Magic-User’s Personal Artifact
• During training the apprentice magic-user created a small minor magical artifact for themselves (a small wand or sceptre or similar object). It is essentially similar to a ring of spell storing in functionality (see B/X Pg. X49), but much weaker and more limited except the stored spells can change as the owner chooses. They can only ever possess one of these at any given time.
• It is light and relatively small but also is quite fragile and easily broken. It must be kept on the magic-user’s person or in very close proximity at all times (e.g. in the same bed when sleeping) to retain it’s ‘charge(s)’.
• It is only usable by the magic-user who created it. To anyone else it will just appear as a harmless, inert, object that serves no purpose (although it will give off an imperceptible to weak magical aura, depending on how many spell levels are currently stored in it, under a detect magic or similar spell).
• It can store a number of spell levels equal to the magic-user’s current highest available spell level. So for a 5th Level Magic-User who can cast 3rd Level Spells, their artifact (wand) can hold 1 x 3rd level spell, or 1 x 2nd Level & 1 x 1st Level Spell, or 3 x 1st Level Spells.
• To charge it the magic-user must specifically cast their own spells ‘into’ it. It can’t be used to ‘catch’ enemy spells on the fly directed at the magic-user. Spells in the artifact will remain their indefinitely until either (a) they are used, (b) the magic-user is separated from the artifact for more than the briefest moment, or (c) it is destroyed. The magic-user can recharge it (fill the empty capacity) at any time by casting the relevant spell into the artifact from their memorised spells.
• To use it, it is treated as if a wand for character actions and any effect is saved against as a wand (not a spell); but in all other respects when the chosen stored spell is discharged it is as if cast by the magic-user themselves at that very moment (including the caster level).
• The artifact may be broken easily due to its fragility from the character having a major fall or suffering some other major impact*, or the magic-user may even choose to deliberately break it in desperation as a combat last resort. When it breaks the energy explodes (akin to a fireball but of magical energy rather than fire):
  • It inflicts 1d6 per spell level of damage per spell level currently stored in the artifact.
  • It affects everyone within 10′ per spell level currently stored in the artifact (incl. the magic-user and any friends).
  • A save versus Dragon Breath halves the magical explosion damage for each recipient.
• If destroyed the Magic-User can recreate the artifact given suitable time and expense (and being in a suitable location to safely focus on their work without interruption). It takes a magic-user 1 day per character (magic-user) level and costs 1,500gp per casters spell level in material and consumables to fashion a replacement personal artifact. e.g. A 5th level magic user who can cast 3rd level spells will take 5 days and 4,500 gp to remake their personal artifact.

* Communication distance for the familiar is suggested to be 60′ (indoors) or 60 yds (outdoors) per level of the magic-user. So a 5th level magic-user can communicate with their familiar up to 300 feet or yards away respectively.

See my post on the Old School Magic User for more related to these 2 concepts – both inspired by Daniel at Bandit’s Keep.

Thief Ability Score Bonus Adjustments

Thieves gain bonuses to their base thief ability scores based on their character abilities. The bonus is based on the standard ability score adjustment scale (with some modifications) and for each thief skill a different character ability provides the modifier. The ability score which modifies each thief ability is listed below, followed by the modifier amount:

• STRENGTH: Climb Sheer Surfaces.
• INTELLIGENCE: Remove Traps, Read Languages.
• WISDOM: Find Traps, Hide in Shadows.
• DEXTERITY: Open Locks, Pick Pockets, Move Silently.
• CONSTITUTION: Hear Noise.
• CHARISMA: —

Ability Adjustment amount for the above Character Abilities/Thief Abilities:

• 13-15: +1 Hear Noise, +1% Climb Sheer Surfaces/Read Languages, otherwise +5%*
• 16-17: +2 Hear Noise, +2% Climb Sheer Surfaces/Read Languages, otherwise +10%*
• 18: +3 Hear Noise, +3% Climb Sheer Surfaces/Read Languages, otherwise +15%*
• 19+: +3 Hear Noise, +4% Climb Sheer Surfaces/Read Languages, otherwise +20%*

* For all abilities except Hear Noise & Read Languages, the Character Ability Adjustment can’t raise the ability score over 95% – that can only be done by reaching the appropriate thief character levels that provide scores higher than 95%. In those cases the thief’s ability is temporarily capped at 95%.

See my post on Old School Thief for more thoughts related to this.

Final Thoughts

There are numerous ideas I don’t especially like and aren’t interested in at this time, these include the concept of damage by class or the default everyone does d6 damage. I like the variable damage based on weapon and that classes are restricted to certain weapon types. It doesn’t mean they are bad, just they aren’t what I prefer at the time of writing – but the damage by class argument is very compelling (especially if aiming for ‘rules light’ play). I actually think the Thief in B/X being able to use any weapon is also possibly an error and was simply overlooked, but play this as written as it doesn’t appear to be an issue.

Like everything my views on these all may change over time; from play experience, the different arguments and discussions around OSR style games from experienced DM’s and bloggers, and my changing personal preference around the style of game…

More Sources & House Rules

These are some of the places I got my ideas from:

• Rambling Cleric: B/X D&D House Rules
• John Arendt’s Dreams in the Lich House: House Rules for B/X and Weird Fantasy Roleplaying