Low Fantasy Gaming, a review

This is a largely 5e-compatible ruleset that borrows a lot from old-school D&D and the OSR. And that's the kind of space I like to dabble in, so let's hop in!

This is a review of the free PDF of the 2016 basic edition. Since you can read it yourself for free, this review, while long, won't be as in-depth as my Let's Read of Best Left Buried. There's currently a kickstarter for the Deluxe Edition, in its final week. So if this review is rushed in places, I'm sorry, I wanted it out before the kickstarter ends.

TL;DR this ruleset did not grip me enough to back the kickstarter, but I would happily play it if a GM or my players suggested it. The bits that appealed to me are super easy to lift for other D&D-ish games. It's easy to learn if you're versed in 5e, though there's some interesting differences (including basic mechanics) that I'll cover below.

What Low Fantasy Gaming Promises

• Rules-light, rulings over rules.
• Fast combat, encouraging creativity over carefully delineated spells or powers. If you hate 5e's already loose combat maneuver rules (as compared to 4e or 3.5/PF), this will not be your cup of tea.
• Dangerous and gritty. Expect injury tables.
• A "Realistic" World. Magic and monsters are rare, PCs and villains are humans more often than not.
• Dark & Dangerous Magic. The basic rules have only one spellcasting class, and the Deluxe rules only have two. Magic is risky. Permanent magic items are rare. Expect wild magic tables.
• Riches & Glory. You're treasure hunters exploring the unknown, not the Epic Chosen Heroes.
• Open World. Sandboxy, episodic adventuring. Not that 5e has any mechanics that push long, arc-based storytelling *shrug*
• Generic Ruleset. The author has his own Midlands setting, but the rulebook can be used for various low magic &/or swords-and-sorcery settings.

Character Generation

The game uses the classic D&D ability scores, except Wisdom is split into Willpower and Perception. One score is automatically a 15, the rest are rolled on 4d6b3 as with 5e. The player chooses where scores go. There are no ability score adjustments for race, in fact, having races at all is entirely optional.

Ability score modifiers are closer to those of BX D&D rather than 3e/4e/5e D&D. e.g. an ability score of 9-12 maps to a modifier of +0, and 17-18 maps to +3.

PCs and monsters have a Luck stat, used for saving throws and as a character resource. It fuels martial exploits, but the text suggests playing free and loose with it, e.g. make a Luck roll to choose which monster to summon with a spell instead of it being random. Luck is always set to 10 + half level (round up) at the start of an adventure, but is depleted by 1 with every *successful* Luck check. A long rest only restores 1 Luck point.

PCs also have a Reroll Pool equal to their level, used for trained skills, various class abilities, and on rolls to avoid dying if the character hits 0 hp. Honestly I don't see why this couldn't have been merged with the Luck stat. It's difficult to remember which rules and abilities deplete which resources.

No Alignment, and no Backgrounds in the 5e sense. Instead, each PC rolls on a table of Bonds to generate connections with at least one other party member. e.g. you were both "lone survivors of the Blackbrand Mercenary Company, destroyed in a recent engagement with their bitter rivals, the Shen-Zu Raiders."

There are five classes, Barbarian, Bard (not a spellcaster), Fighter, Magic-User, and Rogue. The Deluxe rules are adding Artificer, Cultist, Monk, and Ranger.

There is no multi- or dual-classing, but every 3rd level, each class gets an open-ended "make up your own ability" feature, which includes the explicit advice to crib ideas from other games, pick "cross class" abilities if wanted (so... kinda like 4th edition), or just increase an ability score by 1 if you prefer a simpler character sheet. The Deluxe Edition promises 36 pre-made abilities for those who don't fancy designing/balancing their own.

Classes follow the "no dead levels" philosophy of later-edition D&D, getting a new feature (or spell level) at every level. The classes are all roughly the level of complexity of a 5e class, and most features are clearly written. They're all roughly what you would expect from playing 5e -- a barbarian can choose to enter a rage, a bard buffs their allies, etc. Magic-User can take healing spells and some other cleric staples.

All classes can contribute to finding traps and disarming them. All classes have Detection (the former) on their skill list, while Bards, Fighters & Rogues have the Traps & Locks (the latter) on their list. The Rogue has no class features making them extra-good at disabling traps, though they (and any class) can take such abilities with their open-ended slots.

Similar to B/X, all classes cap out at 12th level. They also all get a "stronghold" type feature at 10th level. No level titles though ;-)

You roll for starting money which is used to buy equipment. This is made more awkward by the fact that prices for equipment (though not weapons or armour) are rolled randomly, e.g. an acid vial costs 5d10+50 gp. I prefer either the "equipment package" approach of 5e, the random items of a system like Maze Rats, or Into the Odd's table lookup method. If you want to stick with the shopping method, decide if you want lots of rolling for prices, or rule that items cost their average when bought during chargen.

Task Resolution

Attack rolls are your typical d20 system rolls. Roll d20 + your attack bonus + relevant ability modifier, equal or exceed the target's Armour Class. Melee is always Str, ranged is always Dex, i.e. there are no finesse weapons, and the few spells which call for an attack roll don't base that roll on Int.

Unlike 5e, there is no unified Proficiency Bonus. Different classes have different attack bonus progressions: Fighters & Barbarians (and monsters) have an attack bonus equaling their level, while the other classes have a roughly 2:3 progression. You add your Str or Dex modifier to that, as appropriate for the attack.

Ability checks are *roll-equal-or-under* the relevant ability score. A relevant skill proficiency adds +1 to the ability score, and more importantly lets you spend a use of your Reroll Pool to reroll a failure.

The winner of an Opposed Check is whoever rolled under their ability score by the most. e.g. a beastman (Dexterity 10) is trying to hide from Linda's Fighter (Perception 15). The beastman rolls 7, Linda rolls 15. Neither failed the roll, but the beastman succeeded by 3 and Linda by 0, so her Fighter fails to spot the monster.

Saving throws are roll equal or under your current Luck score + the relevant ability score modifier. Recall if you succeed on the save, your Luck then decreases by 1. This means saving throws vs spells are more like the old-school norm. A 12th-level caster's fireball is no harder to resist than a 5th-level caster's, though it will certainly deal more damage!

Situational modifiers generally range from +2 to -2, though some rules like three-quarters cover grant larger modifiers, and there's the now-ubiquitous Advantage/Disadvantage mechanic. There are suggested rules for Group Checks (i.e. everyone succeeds if at least half do) and Degrees of Success/Failure, though unlike PbtA games and the like, there's no "succeed at a cost". There are also rules for Chases. They boil down to a 4e-style skill challenge, with a random event/obstacle/complication table that gets rolled on each turn.

Overall, task resolution is based on functional, well-understood ideas, but the mix of d20 system rolls and d20-roll-under is needlessly complicated. I love d20 roll-under, but if you're going to use that for ability checks, may as well use it for attacks as well a la Whitehack, The Black Hack, or derivative games.

Combat

1st-level characters don't have maximised HP. As with old-school D&D, after 9th level, characters only get +1 or +2 HP per level, no Con modifier. That and the different ability modifier scale means characters will have slightly less HP than in 5e. It isn't quite as brutal as BX and similar games though -- Hit Die results are limited to the upper half of their range. e.g. the Fighter doesn't roll 1d10 + Con each level, instead they roll 1d5 + 5 + Con.

Player turns in combat do look like they'd be kept fairly short despite the feature-heavy classes. Fighters and Barbarians can make an Extra Attack starting from Level 7, but each usage costs a point from their Reroll Pool. There are no bonus-action or reaction spells, and combat maneuvers either trigger on a natural 19 or are made in addition to an attack. Not all the tactical consideration is removed -- players will still be choosing what resources they're OK depleting (HP, Reroll Pool, spells, limited rages/bardic inspirations/day).

Combat follows a typical d20 system structure. Each character acts on their own individual initiative, rolled on a d20 unmodified by any ability score, though some weapons and other effects adjust Initiative).

Unlike 5e, you cannot move before and after your action.

Attacks of opportunity (called "free attacks") exist, but are provoked only by moving out of an enemy's reach (*not* moving out of each/every square within enemy's reach, as with 3.5) and by critical fumbles. Casting a spell doesn't provoke them.

Rolling poorly on initiative is bad for spellcasters -- you can't cast a spell at all if you've already been hit that round.

The weapon table has a similar number of entries to 5e, but the rules for each weapon are generally more complex. Many grant bonuses to certain rolls, and/or have a special ability that triggers on a natural 19, e.g. a heavy crossbow will knock enemies prone.

Attack rolls crit on a natural 20, dealing max damage + 1/2 your level. A natural 1 is a critical fumble, provoking a free attack from an enemy in melee or possibly hitting an ally instead.

Damage is based on weapon, not class. There are no Finesse weapons -- all melee attacks are made with Str, all ranged with Dex. Anyone can two-weapon fight -- unlike 5e the off-hand attack is made at disadvantage but adds Str modifier to damage. Unlike 5e, crossbows deal lots of damage but take your action to reload.

As with 5e, Armour Class is 10 + Dex modifier + armour bonus, but your full modifier is added regardless of armour type. Shields give a +1 bonus, but a player can also simply declare that a shield negates an attack. This ability cannot be used again until the shield is repaired back in civilisation, but the shield will usually continue to provide its +1 bonus.

Combat maneuvers (here called Exploits) are handled as case-by-case GM rulings. Minor Exploits with a 1-round effect (e.g. throwing sand in someone's eyes) are handled as follows: attacker states desired effect, then makes an attack. If it hits, it deals damage as normal, then an Opposed Check determines if the desired effect happens. Major Exploits (e.g. severing a limb) are available to PCs only, have some guidelines affecting their power (e.g. no single-target extra damage, no instant death/incapacitation unless the monster has Hit Dice less than PC's level), and call for a Luck Check instead of an Opposed Check, so are limited in use.

I really like these Exploit rules. They're not as constrained as, say, 4e martial powers or 5e's Battle Master Fighter archetype, but have more guidance and dwindling Luck management than just being a really permissive GM towards Champion Fighters, which is my usual approach in 5e.

The game borrows 4e's bloodied mechanic (called staggered here). Some PC and monster abilities care about whether a creature is staggered.

You are unconscious and dying at 0 hp. After combat (or once your body is hauled out of danger) an ally can tend to you. You then make a Con check (not a Luck save). If you fail, or if no ally is around to rescue you, you're dead. If you succeed, you're stable and will wake on 1 hp in 1d3 minutes, and make a roll on the Injuries & Setbacks table. Note that while magical healing works instantly if the target is above 0 hp, if used on a 0 hp creature, it takes 1d3 minutes to work. Once someone hits 0 hp, they're out of the fight.

Adventuring

Short rests are only a few minutes, rather than 1 hour. You are limited to three short rests every 24 hours, and each one allows you to roll a different number of Will checks: 1, 2, or 3, plus extra checks per day equal to your Con modifier, distributed among the three rests as you see fit. For each successful Will check, you either:

• regain half your lost HP + your Con bonus
• regain a limited-use class ability or spell slot
• restore 1 point to your Reroll Pool.
  

Honestly the accounting here is a bit complicated here, and I would immediately houserule it. Three rests, make one Con check for each one. Success means you choose two of the above benefits, failure means you choose only 1.

I am unsure about the shortened rest duration. I like how a short rest in 5e is long enough to incur at least one wandering monster roll, but also understand the desire to encourage players to push on instead of retreating & making camp for the day.

A long rest, on the other hand, takes 1d6 days (1d4 in an inn), recovers pretty much everything (including attribute damage), except only 1 Luck is regained, and you only regain slightly more than half your lost HP. This is fine, though with 3 short rests/day plus healing magic I'd just handwave everyone goes back to full HP.

There is even less emphasis on inventory management than in 5e D&D. The Fighter even has a class feature (useable 1/adventure) that lets them retroactively have brought along the right mundane equipment for the situation. There are no guidelines for how much items weigh, how much stuff a person of a given Str (or Con) can carry, or how they are affected if they approach/exceed this amount.

(I'm kinda OK with this. People with strong opinions on the importance of encumbrance also usually have strong opinions on their preferred subsystem for modelling it, and for everyone else, GM fiat is good enough)

There is no XP. Levelling-up happens after every adventure, assuming the character meaningfully participated. There's optional rules for acquiring parts of your next level (e.g. the extra HP, class abilities, or reroll die) after each session.

GM-Facing Stuff

NPC reactions and morale are handled with Cha and Will checks rather than the 2d6 rolls of old-school D&D. This is fine, but I'd use degrees of success here -- binary "friendly/unfriendly" is less interesting than the old-school reaction results of "hostile, unfriendly, unsure, indifferent, friendly". Some monster abilities, e.g. magic resistance, are handled with percentile rolls.

Wilderness travel speeds and encounter distances by terrain type are provided, but no B/X-style procedures for hexcrawling, getting lost & veering course, weather at sea, etc. This is probably not the ruleset for you if you're interested in playing a game about the journey, not just the episodic adventures that punctuate it.

Traps are divided into Simple Traps, and more setpiece Complex Traps. There are no "hazard/trap severity by level" guidelines as with later D&D editions. Clever narration of a PC's actions can find Simple Traps without a Perception check, and it's suggested that Complex Traps telegraph their presence before they activate. Good advice, wish more DMs would follow it.

Magic

The big change is that casting magic is always risky. Whenever a spell is cast, the caster rolls a d20. A natural 1 causes a roll on the Dark & Dangerous Magic table and a loss of one Luck point, but the spell is still cast. If no DDM effect occurs, the odds of DDM increase by 1 for subsequent rolls. When a DDM effect finally happens, the DDM chance resets to 1 in 20.

The rules are unclear whether one DDM number is used to track all PC and NPC casters, or if each has their own DDM number. I could see either choice being fun.

The DDM table is full of creepy/sinister effects rather than the lighthearted goofiness of the 5e Wild Magic table. Some mechanical benefits, some banes, and some that have no mechanical effect but which could definitely influence play direction. For some reason, "an enraged [monster appears for 1d4 minutes]" has multiple entries in the table, even though the table is already d100 with varying odds for different entries.

I like the DDM mechanic. I know some people aren't a fan of how 5e Wild Magic Sorcerer triggers their magic surges (i.e. the DM just says a surge happens, then gives the sorcerer their special reroll back). This is a good alternative that is applicable to all spellcasters. And some of the DDM table entries are great, e.g. "Heartless: You have no discernible heartbeat, and do not bleed. The effect lasts 1d12 months.", even though I overall prefer the goofiness of the 5e table.

The rest of the magic system changes are more subtle:

Magic-Users cast spells like a 3e Sorcerer, or 5e non-warlock class, i.e. spontaneous casting from your known list, not strictly Vancian fire-and-forget casting.

Magic-Users have no cantrips, but otherwise have a similar number of spell slots to 5e wizards (though remember a long rest is 1d6 days!). Int is always their casting stat, but this has minimal effect on their spells' effectiveness. I only spotted it counting towards HP healed by Cure Light Wounds or Cure Serious Wounds, and to a Luck(Int) check that Dispel Magic instructs you to make. Int does determine number of known spells (Int mod × character level) + 1. In a nice touch that pushes adventurers towards dungeon delving, magic-users get an extra known spell each level-up if they have new tomes, scrolls etc to pore over.

Each spell level has 20 listed spells, which are numbered. Anything that aids random generation is good. Some spells can be reversed, as with older D&D editions.

There's no casting a spell as a ritual to save the spell slot. Some spells like Detect Magic have much longer durations to compensate, a nice attention to detail. Similarly there's no "Duration: Concentration" spells. You can maintain as many spell effects as you have slots to cast them with. There are also no "At Higher Levels" entries for spells -- they automatically scale with the caster's level, such as Fireball, or they don't scale at all, such as Sleep.

The spell text is a mix of old and new, e.g. Thunderwave is in there, but so is Protection From Normal Missiles. Fireball will shape itself to the available volume, Lightning Bolt doesn't bounce off walls though. The damaging spells are closer to their AD&D and 3e text than to 5e, e.g. Magic Missile produces 1 missile every odd caster level, instead of 5e's 3 + 1 per higher-level slot. Sleep affects 4d4 Hit Dice of creatures, rather than affecting creatures by current hit points as in 5e.

Magic-users can learn elemental variants if desired, e.g. Frostball instead of Fireball. Researching unique spells is also briefly mentioned as a possible downtime activity. Sometimes players need explicit permission to come up with new stuff, make the game their own, so this is good. Monsters rarely have elemental resistances or vulnerabilities, so modding spells doesn't cause any balance issues.

The Deluxe text (and the Midlands setting) renames a bunch of spells, e.g. Hold Person becomes Crush of the Warp. This may or may not suit your tastes.

Resurrection magic is deliberately absent, as is long-range teleportation and lie detection. Dimension Door is in there, but unlike 5e, requires line of sight to the destination.

A couple of original spells are quite nice: Ritual Magic is a catch-all for long-term warding spells like explosive runes, while Forbidden Wish can duplicate lower-level spells, or strike a bargain with an otherworldly being for a more powerful effect, incurring a debt, madness, and Con loss.

Overall this keeps magic relatively simple, not as easy to teach as Knave's system, but closer in power level to 5e with less of its fiddly specifics.

Magic Items

Permanent magic items are meant to be rare, most magic items should be potions and spell scrolls. Unlike 5e, anyone can cast from a scroll. But if you're too low-level (or not a Magic-User) you make an Int check or the spell goes awry, rolling on the DDM table instead. This is basically how I houserule scrolls in 5e anyway, so this change is welcome.

Because permanent items are rare, there's no equivalent to 5e's "max 3 attuned items" rule. "Attunement" in this ruleset refers to the tendency of permanent magic items to gain extra powers as an owner continues to wield them. The rate at which these powers might be unlocked, and/or any requirements for them, are left to the GM to decide.

Instead of a list of "canonical" permanent magic items, the game provides a random table of item types, and two random tables of item properties, one obvious, one discreet. Items have a 2 in 3 chance of being discreet in their nature, but there are 20 listed discreet properties and 34 obvious ones, which is a bit back-to-front? Probably still enough to get you through a campaign or two before duplicate effects get rolled. Many properties, when used, cause a DDM roll to be made after their use. Many properties mimic a spell, these generally can only be used every 1d4 days, but aren't subject "if you've been hit this round, you can't cast spells" rule.

I just rolled up:

• a Storm-Calling Greatsword that can change the weather within 10 miles to anything short of catastrophic (i.e. no cyclones) for 1d4 days. It requires a DDM check each day the unnatural weather persists.
• a Telepathic Cloak, that lets you mentally communicate at will with creatures, causing a DDM roll after every conversation.
• a mysterious scaled egg, the size of a child's fist and warm to the touch. Its possessor can treat themself as trained in any skill, but must make a DDM roll each time they use this benefit.

Pretty functional way to quickly put together treasure for a one-shot :-)

Random Tables

I covered the Dark & Dangerous Magic and Magic Item tables above. This book has plenty of other random tables, most of which are either system-neutral or trivial to adapt to your game of choice.

I like the 1d20 list of Bonds for connecting PCs with each other. e.g. you were both "Indentured gladiators of the dreaded Ogorien Fighting Pits". This is much faster and easier to bring up in play than 5e's Ideal, Bond, Flaw system.

The Injuries & Setbacks table (rolled on if you hit 0 hp but survive) is rolled on d20, has 13 injury effects, 3 "damaged equipment" effects, or is just a minor scar on a 17+. Some entries cause ability score damage, requiring recalculation of modifiers. Others cause a roll on a separate Madness table. Otherwise, pretty straightforward.

The Chase Events table is quite useful. I prefer Whitehack's auction mechanic for chases over the skill-challenge mechanic here, but will pinch this table for spicing up the former.
A d30 table of paragraph-long dungeon room entries, generally pretty evocative and good in a pinch.

The Madness table has no associated mechanical penalties/benefits, leaving that up to player/GM suggestion. There is a minor mechanic for madness progression/remission, i.e. more or less frequent triggers. The spell Cure Malady can weaken a madness one stage, or cure a madness on the lowest stage.

The Carry Loot table (i.e. "I loot the bodies") entries are generic, though I guess you don't want every slain brigand to be carrying bizarro trinkets and cursed gold. The Trinkets & Curios table is excellent at building out the world in unpredictable ways. The Valuables table is somewhere in between, there's some description but far fewer of them will spark unusual play directions.

The Random Encounter tables are pretty solid, unlike some games the author actually realises not every encounter should be "raar, a monster attacks". There's advice for new GMs that not every rolled monster should be approached as a combat encounter. The City/Town/Village table is almost entirely non-combat (though could certainly escalate into it). A few entries are basically just local colour, but a lot more entries will likely drive play forward. The wilderness tables are 70% monsters, 15% hazards, 15% oddities/adventure seeds. The tables deliberately avoid providing "level appropriate" encounters. Monsters usually have a stated behaviour or motivation, even if it's just "hunting for food" or "camping", these are better prompts than just saying "1d6 fire beetles".

There's a better idea density in the encounter tables than in, say, Xanathar's Guide to Everything. But they felt very typical low-mid level D&D to me, not the "monsters are rare, most threats are human" that was promised. This isn't necessarily bad -- I'd use these for a Forgotten Realms or Skyrim game, just not a Westeros or Middle Earth game. Maybe the Midlands setting book has different encounter tables?

Monsters

These have simplified stat blocks closer to old-school D&D. Their Hit Dice (always d8) also count as their attack bonus. Ability scores (including Luck) are provided for the purpose of ability checks, but modifiers to attack, damage, etc are ignored, and monsters don't have skills. Special weaknesses and powers are usually described in accompanying text rather than the stat block. Each monster has a special ability that triggers on a natural 19 attack roll, e.g. an ogre mage can summon spirit warriors, a roc might grab a target and fly away, some other monsters just force a roll on the Injury & Setback table.

I like this "take the load of tactical analysis off the GM by having monster abilities proc randomly" idea -- speeding up the GM's turn and getting back to players is always good. But I would increase the odds for a lot of these abilities. 5% per attack is pretty low given how many rounds combat usually lasts, e.g. 3 rounds means only a 14% chance the monster's neat trick will come up.

Guidelines for turning any monster into a Boss Monster are provided: double HP, immune to Major Exploits unless staggered, a Reroll Pool same as adventurers, Off-Turn Attacks, and special powers of the GM's design.

Most of the provided monsters are standard D&D-isms, which is useful for compatibility purposes but undermines their scariness for all but the newest players. Converting monsters, either from 5e or OSR games, is trivial though, so that's not a huge problem. A few nods to classic tropes, e.g. dragons automatically smelling all living things within 60 ft, make some entries feel more alive than 5e's more sterile "blindsight 60 ft" text.

Conclusion

There's a lot to like in this game, and it's very easy to pick and choose the bits you like and apply them to other d20 games. Creating a character is faster than in 5e, most classes don't have spells, the spellcasting rules are easier to explain than 5e's are. Dark & Dangerous Magic and the depleting Luck resource are fun mechanics, death & dying is more threatening than 5e, but magical healing still isn't necessary to have. PC and monster combat abilities are worded so as to avoid combat slowdown, while the Exploit rules provide just the right level of guidance for me.

But I'm underwhelmed by task resolution being a mix of typical d20 system rolls and d20-roll-under, by the game having both a Luck stat and Reroll Pool, by some aspects of the combat system, by the resting rules.

I would happily play in a LFG campaign, or run one if players specifically requested it. But if I ran it, I'd be inclined to houserule a bunch of stuff, and at that point, choosing this over 5e or Whitehack makes a lot less sense without some external factor pushing me to do so. And if I specifically wanted swords & sorcery, Sharp Swords & Sinister Spells provides at least as many tools to emulate that genre as LFG does, while being a much lighter ruleset.

I won't be backing the Kickstarter, but I will keep an eye out for the Deluxe version once it's available for non-backers & see if I like it more. I also want to read more of the Adventure Frameworks -- I bought one and it's gone straight into my pile of one-shots, so it's pretty likely I'll buy and read the Midlands setting book sometime soon.

Skyrabbits (monster for BX & 5e)

Midnight-blue rabbits whose lustrous fur twinkles with motes of light. They can burrow through any earthly material, their bodies subject to no mortal poison. They live in the firmament, grazing on moonsilver vegetation growing inside the cavernous pinprick holes that let in starlight from beyond.

"When I was a wee boy, the sky fell.

"The sages say an armada from beyond the stars came to breach our "crystal sphere", whatever that is. Whatever they were, they failed, but their cannons or whatever must have blasted fragments of the sky itself down here. Now the sky grew back, else I wouldn't be here, but those fragments were riddled with skyrabbit warrens.

"They burrow through anything with ease: wood, stone, even steel. Our world must be nothing to paws and teeth capable of digging through the sky itself. Rumour has it even the wizard Arthras, one of the few still able to conjure the fabled Wall of Force, was unable to repel an infestation from his demesne. Supposedly his tower stands abandoned, its foundations doomed to collapse any month now.

"Their fur's easy to spot, and they're worth a small fortune even once the twinkle wears off. But not even wolves can catch them, and they shrug off any poison. Caught one in a trap once, but it just gnawed through the metal, leaving only shining purple blood behind. Occasionally some big military commander captures a few to dig into an enemy castle or something. But the breeding stock always gets loose again, letting the bastards loose on yet more soil.

"There's a ranger stalking these parts, follows the Old Ways. She says the world itself rejects these beings of aether, that they cause reality to erode. I've seen it, I think. The soil near their warrens, just... decaying into its fundamental parts. She says that if they're not stopped, eventually the skyrabbits might destroy the world as we know it.

"I'll be long-dead by then though. Just m'bones, drifting through the stars. Sounds neat."

Skyrabbits in B/X

Note: [square bracketed] stats are for use with systems with ascending AC and/or unified saving throws

Armour Class: 7 [12]
Hit Dice: 1⁄2 (2hp)
Move: 150’ (50’), 60’ (20’) burrowing
Attacks: 1 × bite or kick, 19 [+0] to hit
Damage: 1
Saves: as normal human [18], Death 14 Wands 15 Paralysis 16 Breath 17 Spells 18
Morale: 5
Alignment: Neutral
XP: 5
Number Appearing: 1d3 (3d6)
Treasure Type: None

• Flighty: Unless magically summoned or controlled, skyrabbits check morale every round.
• Glowing pelt: Sheds light for 10 ft. Continues glowing for 1d6 days after death. 
• Immunity: Unaffected by common poisons.
• Keen smell: Automatically smell silver, otherwise only surprised on a 1.
• Peerless burrower: Can burrow through any known material, including magic forcefields.

Skyrabbits in 5e

Tiny beast, unaligned

Armour Class 11
Hit Points 3 (1d4 + 1)
Speed 40 ft., burrow 20 ft.

STR     DEX     CON     INT     WIS     CHA
4 (−3)  12 (+1) 12 (+1) 2 (−4)  14 (+2) 14 (+2)
 
Damage Immunities poison
Condition Immunities poisoned
Senses darkvision 30 ft., passive Perception 12
Languages --
Challenge 0 (10 XP) 

Illumination. The skyrabbit sheds bright light in a 10-foot radius and dim light for an additional 10 feet. The pelt continues to shed light for 1d6 days after the skyrabbit dies.

Keen Smell. The skyrabbit has advantage on Wisdom (Perception) checks that rely on smell, and automatically smell silver.

Peerless Burrower. The skyrabbit can burrow through any material, including walls of force and similar effects created by mortal spellcasters.

Actions

Bite or Kick. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 1 piercing or bludgeoning damage, as appropriate.

Ten Puissant Relics for Knave and Other Games

These are written for Knave, intended to fill the niche of at-will magic abilities that 5e players (and tbh, most fantasy readers unfamiliar with the peculiarities of Vancian magic) often expect.

As such, the ones that deal damage are roughly balanced against that system's existing ranged weapons, often taking an extra item slot to account for non-combat utility, having worse quality, or having restrictions on their use.

My goals were:

• call out a specific noncombat usage, without ruling out other creative possibilities. e.g. the Electromagnetic Gauntlet attracts ferrous objects, but could potentially also be short-circuited to start a fire (probably at the cost of immediate loss of quality)
• try to write items that say something about the setting and the wielder’s relationship to it. A Carabid Ring is granted to every graduate of the arcane college of Entomon — are you a graduate or did you just shank one in an alley?
• provide easily extractable mechanics information, but also write item descriptions using natural language, and as system-neutral as possible.
• text I can release (once it’s fully-baked) under Creative Commons (CC BY 4.0), i.e. not based on the text of any 5e cantrips or anything else OGL.

Let me know if you find these useful, either in your Knave games or adapted to the game of your choice.

1. TABLET OF LAW

2 slots, 1 hand, quality ❑❑❑❑
Commune with Deity: 1 turn to cast, learn local deity’s commandment (tablet holds up to 5).
Speak Commandment: Int vs Cha, force creature to obey commandment for L turns.

This clay tablet still burns cold with the pale flame of its divine firing. Cuneiform marks corresponding to no mortal tongue swim across its surface, reflecting the laws of powerful local gods. If a city worships Jupiter above all others, the tablet will reflect this, but as one nears the city gates, the tablet may show Janus’s will instead.

The tablet’s bearer can spend 10 minutes to commune with the tablet and “fix” one of the local deity’s laws in an intelligible form. A deity might have multiple teachings, but the tablet can hold at most five. Fixing an additional law requires the tablet to “forget” a previous one.
 
The bearer can utter any of the tablet’s fixed laws to attempt to compel a creature to obey it for a short time.

2. SIX COWRIE SHELLS

1 slot, 1 hand, quality ❑❑❑❑❑❑ (each loss indicates a destroyed shell)
Illusory Monster: conjures random illusion, which disappears if struck. Caster can use action to direct illusion to move 40 ft and/or make a melee attack (caster’s Int vs Cha, d6 damage).

Six cowrie shells plundered from an enormous board game in some forgotten king’s tomb. When thrown, will conjure an illusory monster — the more shells that land aperture-up, the more dangerous-appearing the illusion will be. The illusion fools sight and hearing, but is intangible and cannot interact with objects.

Regardless of form, the illusion moves as fast as a human. The wielder can direct the monster to move and/or attack a creature. Being an illusion, it assaults the victim’s mind. The monster vanishes when struck with an attack, including harmless “attacks” like tossing a pebble through it.

Thrown shells must be retrieved before they can be thrown again. Throwing fewer shells is possible should the owner so desire, or in the event some shells are lost or destroyed.
 
The following monster suggestions are from BX: Essentials: Monsters, number of shells landing aperture-up corresponds to monster Hit Dice (rounded down).
0 — normal rat, normal bat
1 — giant ferret, skeleton
2 — rock baboon, pit viper
3 — mountain lion, grey ooze
4 — dire wolf, wraith
5 — cockatrice, owl bear
6 — manticore, white dragon

3. CARABID RING

1 slot, 1 hand, quality ❑❑❑
Caustic Spray: Int vs Dex, 1d4 damage to up to 2 adjacent creatures/objects within 20 ft.
Animate Beetle: beetle-construct animates, can be given 3-word commands.

This fine silver ring is set with a life-size bombardier beetle carved from jet. It is given to all graduates of the College of Entomon, a magic school feared for their uncanny control over insects. As an action, the wearer can command the beetle to unleash a spray of boiling caustic fluid, or cause the beetle to animate and leave the ring. An animated beetle can carry 1 pound, and be given 3-word commands.

4. LEADEN SKULL OF THE DAMNED ALCHEMIST

2 slots, 2 hands, quality ❑❑❑
Transmute Object: Turn object to lead for 1 turn or until used again.
Transmute Creature: Int vs Con, 1d8 damage and slowed to 1/3 movement for 1 round. 40 ft range.

The skull of some wretched alchemist who erred in his attempt to create the Philosopher's Stone, the resulting Elixir of Life transmuting his bones to lead. A flicker of golden flame in its empty eye sockets indicates some remnant of the false Stone's power remains.

The wielder can hold the skull aloft and use its pale golden gaze to transmute an object to lead for 10 minutes or until the gaze is is directed elsewhere. Living creatures are more resistant, and will only partially transmute for a few seconds, if at all. A creature thus affected has its movement reduced to 1/3 of normal, and is effectively poisoned by the disruption to its physiology.

5. EMBROIDERY HOOP OF THE TOURMALINE COURT

1 slot, 2 hands, quality ❑❑❑
It takes 1 turn to prepare a usage of either of the following, but only 1 action to cast.
Glyph of Pain: Int vs Armour, d6 damage, 40 ft range.
Plush Conjuration: create plush version of an object, appears adjacent to you, lasts 1 turn.

A well-used pair of concentric whalebone hoops, holding taut a magic cloth woven from the fleece of the mythical Vegetable Lamb. Created as covert magical tools for the ladies in waiting of the Tourmaline Court, the secret of the hoop’s enchantment was lost when that kingdom fell.
 
The hoop is found with 3d6 feet of alchemically treated thread, enough to stitch that many motifs. Additional thread must be created in a safe haven, and costs 100 cp per foot.
 
Stitching a motif into the cloth takes 10 minutes. A completed motif immediately disappears, creating a magical effect. A motif can be left almost finished, only requiring a few seconds to complete and activate.

Knowledge of only two types of motif has survived. The Glyph of Pain is a crude sympathetic magic that can injure a nearby creature, while the Plush Conjuration causes a full-sized knitted facsimile of an object to leap forth from the cloth. This object is whatever is represented by the motif’s stitching, and can be no longer than 10 ft in any dimension. It is short-lived, soon decaying into motes of dust.

6. ELECTROMAGNET GAUNTLET

2 slots, 1 hand, quality ❑
Magnetic Pull: 1 action to cast, magnetically attracts wearer and an iron/steel object within 20 ft. Creatures holding such objects may resist (Int vs Str)
Discharge: 1 action to cast, Int vs Armour, d8 damage to a target within melee range

This heavy glove laden with voltaic piles and copper coils taps into the wielder's magical power to augment its crude application of natural philosophical principles. It regularly breaks down.
 
The wielder can attract an iron or steel object from up to 20 ft away. If the object is held by a creature, the creature can attempt to resist being disarmed. The wielder pulls lighter objects toward them, but is themself pulled toward heavier objects.

The wielder can also discharge a stroke of lightning against a target in melee range.

7. MOON STONE

2 slots, 2 hands, quality ❑❑❑❑
Tidal Control: Manipulate water level of lake, sea or ocean by up to 5 ft
Moonbeam: Int vs Dex, d8 damage, must be line of sight between moon and creature

This pearlescent sphere holds mysterious power over the moon. Stolen from a colonised people. They want it back.

The stone has power over the tides, and can call down a baleful moonbeam onto a creature, searing their flesh with a cool radiance.

8. QUICKSILVER SHARD

4 slots, no hands, quality ❑❑❑
Shard Kinesis: move/reshape shard within melee range, can support or exert 5 lb (1 slot) of force.
Forceful Blow: Int vs Armour, d10 damage, melee range.

This alien metal has great inertial mass, but transfers its gravitational mass to its wielder. It thus hovers next to them, but can be telekinetically moved with subtlety, or swung as a powerful bludgeon.

Being a liquid, it can only support 5 pounds of material before surface tension breaks and the material falls through. It is similarly limited in the sustained pressure it can exert when telekinetically pushed against a surface.
 
Unlike mundane quicksilver, it does not alloy with metals.

9. BOTTLED SPIRITS

1 slot, 2 hands, quality ❑ (depleted quality can be restored with a living sacrifice)
Psychic Miasma: Int vs Cha, 1d4 damage
Ghastly Ageing: Int vs Con, target ages 2d20 years for 6 turns or until used again

This odd bottle’s glass surface is etched with geometric binding patterns almost invisible to the eye. A dense purple fog swirls within.

Uncorking the bottle releases a spirit of despair, afflicting a nearby creature. It can either psychically assail its victim, or cause it to age magically. A magically aged creature will age 2d20 years for 1 hour or until the bottle is used again. This can't kill a creature, but it may affect its physical stats negatively, positively (e.g. a child, a dragon) or not at all (e.g. an elven young adult).
 
Occasionally the spirits grow restless, and will cease obeying the bottle’s owner until an intelligent creature is sacrificed in their name.

10. IRON ROSE

2 slots, 1 hand, quality ❑❑❑
Draw Blood: Int vs Con, d8 damage, 40 ft range, creature must already be physically wounded.
Collect Blood: Attracts spilt blood within a 40 ft radius

This rose-shaped haematite crystal exerts an uncanny pull on nearby spilt blood. Any who wield it can even draw blood forth from an open wound with a mere thought. The crystal digests any blood it touches, adding iron to its mass — eventually it will divide in two and spirit one daughter away to find a new master. It knows to do this while unseen.

Let's Read Best Left Buried, part 3

Part 1 covered some basic mechanics, and Chapters 1: Introduction & 2: Making a Character
Part 2 covered Chapter 3: Advancements

Note that the Best Left Buried pdf has been updated since those posts, so some earlier comments may no longer apply. I'll go back and revise once I've finished the book.

Chapter 4: Playing the Game

While I've already covered much of this chapter in Part 1, there's still a lot to elaborate upon. Hopefully this doesn't read too redundantly.

Stat Checks

Remember a Stat Check is 2d6 + relevant stat (Brawn, Wit or Will), trying to roll equal or greater than 9. This covers both active checks (picking a lock) and passive "saving throws" (resisting a poison).

Observation Checks are a special kind of Stat Check with no associated Stat (i.e. just roll 2d6). There is no instruction for the GM to secretly make this roll. It's 2018, players know not to metagame. I like how there's no associated stat. Perception usually becomes a skill tax in other systems, but if that's the intent, it gets undermined by the Advancements that improve Observation Checks (Ears of the Owl, Eyes of the Hawk, Nose of the Dog).
 
Now the rules say "a Stat Check is required when a PC, NPC or Monster attempts to do something that has a chance of failing." This is a pretty standard, 5e-style approach. Compare this to some storygames, that tell you not to roll unless failure is interesting. Or to Into the Odd, which doesn't require a roll to walk a narrow ledge when there's no pressure, and which instructs the GM to automatically mention presence of traps/hazards, unless the character is running, visually impaired, or somehow distracted.

If you want to use Into the Odd's approach (and it is one of the games that the free sample chapter suggests you kitbash with), then you probably want to either buff the aforementioned Advancements related to Observation Checks, or remove them.

The Upper Hand and Against the Odds are this game's equivalent of advantage/disadvantage. I like the attempt to rename them to something that has more natural language, though I've found in the course of this Let's Read that it's harder to construct intelligible sentences with those phrases than it is with the 5e terms. I suspect most players will revert to calling it the latter as well.

Unlike 5e D&D, multiple sources of either AtO or TUH can stack, and only cancel each other out one-for-one. So if there's three separate factors giving me TUH, and one making the situation AtO, it's 3 - 1 = 2, not the normal roll that 5e would have you make.

If you have one or two net instances of TUH during an attack or stat check, you roll 3d6 and use the best two dice. Same for AtO, only you use the worst two dice.

But if you have a net three or more in either direction, the roll either becomes an automatic success or automatic failure, as appropriate. The game calls these Trivial and Impossible tasks.

Now on paper this is more complicated than, say, Maze Rats's approach. But Maze Rats puts a lot of weight on GM fiat in determining whether an attempted action will auto-succeed, auto-fail, or go to a roll. This is an approach I'm comfortable with, but not everyone is. Basically this takes that tacit GM process of deciding "is the players' plan good enough to skip a roll" and adds explicit guidelines.

[I may edit this to insert a flowchart later]

It is also because of this approach that Best Left Buried uses a lower Target Number of 9, compared with Maze Rats's 10. Here's some probabilities in case you're unfamiliar with the amount of difference this 1-point shift makes.

P

In Maze Rats, a starting character making a Danger Roll with their best stat will still fail more often than not. Danger Rolls by design are the unreliable safety net for when the players fail to be sufficiently clever. In Best Left Buried, Stat Checks are more forgiving and an unsure GM can feel comfortable calling for them without screwing over their players.

It bears note that while this system is more complicated than 5e's advantage/disadvantage system, the target number for a stat check never varies. If a lock is particularly challenging to pick, that's an instance of Against the Odds, not a higher target number.

So if you want to run this game (or lift its ideas for another game), decide for yourself how comfortable you are with GM fiat. Simpler mechanics doesn't always mean easier to run, if those mechanics rely on a strong internalised sense of what makes for fair adjudication. Both Best Left Buried and Maze Rats stress the importance of players trying to set up unfair advantages for their characters as opposed to a "fair/heroic fight", they just do the accounting for that in different ways.

Combat

The overall structure of combat is similar to 5e D&D. Every PC rolls their own initiative, the GM rolls initiative for the monsters (using the same roll for multiple identical monsters), and then the combat proceeds in rounds, with characters/monsters acting in order of initiative.

Initiative is rolled on d3 + Wit, adding modifiers from certain Advancements or currently-held weapon types (i.e. Heavy and Long weapons give -1 to Initiative)

There is the suggestion of rerolling Initiative every round to shake things up, but no alternate initiative methods presented (e.g. group initiative like BX D&D, Maze Rats or Into the Odd, The Black Hack's simplified individual initiative, popcorn initiative, or Troika's token bag). The Black Hack's method is most compatible with the weapon modifiers, so I hope the Deluxe version includes that as a variant.

Surprise functions similarly to 5e. A surprised character can't act on their first turn, but isn't easier to hit unless the attacker has something like the Knife From The Shadows Advancement.

The field of combat is represented with Zones instead of a grid. If you're familiar with Fate Core or The Black Hack, you know how these work. You can move one zone each turn, two if you spend your action to move again. Most melee weapons require you and the target to be in the same zone, Long weapons can attack from 1 zone away, and Ranged weapons from up to 5 zones away.

Zones may vary in size by how easy they are to traverse -- there is no separate Difficult Terrain mechanic. For this game's focus (dungeoncrawls full of cramped, pokey corridors) this is fine, but above-ground adventures will require GM rulings about whether a bog that's multiple zones to traverse may count as fewer zones for the purpose of a ranged attack.

Actions

During your turn you get one action. The examples provided are fairly intuitive.

Attacks

You have to see your target, which may require an Observation roll for a hidden/obscured creature. Presumably you don't miss your turn if you fail the roll, you just have to do something else.

Attacks use a more complex roll than Stat Checks:

• The Target Number is variable (7-11), depending on enemy armor. The default score is 8, which I think is also the case for unarmored player characters. The rules could be more explicit and state this earlier in Chapter 2.
• 3d6 are rolled by default. If attacker has The Upper Hand (1 or 2 instances), roll 4d6 and discard the lowest. If they are Against the Odds (1 or 2 instances), roll 4d6 and discard the highest. If it's Trivial or Impossible, the attack auto-hits/misses, as with a Stat Check.
• Any two dice can be used with the appropriate Stat to see if an attack is successful. The unused die is used as the damage roll. This die may be adjusted by weapon type or by Advancements. A natural result of 6 on the damage die indicates a Critical Hit. This doesn't result in extra damage, instead it forces a roll on an Injury Table.
• If the attack is Trivial, to determine damage you roll 2d6 and use the highest die.
  

e.g. I have Brawn +2 and attack a ghoul with 8 Armour, after entangling its limbs in a net. The GM has ruled I have The Upper Hand, so I roll 4 dice, getting 1, 1, 5, 6. I discard one of the dice showing 1. Obviously the 5 and 6 beats 8 Armor, but 1 and 5 with my +2 Brawn will also equal 8 Armor, leaving the 6 left over. So I can deal 6 damage if I want, a Critical Hit!

The game text provides three examples of making an attack roll, which is good for understanding how it works. However this is still one of the fiddlier parts of the game. I would still use the rules-as-written for one session to check if my intuition is correct, but I suspect this is the first thing I would houserule away (probably for Maze Rats's attack rules)

Escaping

If you move out of a Zone with a monster in it, you risk it attacking you outside of turn order, somewhat like 5e D&D's Opportunity Attacks. The wording is unclear whether the same is true for a monster moving out of your Zone.

You can either play it safe and spend your action to safely Escape (no roll needed) or you can make a Wit Check. If you fail this check, you can choose to stay put, or move and incur an Attack from one of the monsters in the Zone. Note you don't incur an attack from every monster in the same zone, instead multiple attacks are handled by the Ganging Up rule.

Ganging Up

Only identical monsters (never PCs) in the same Zone can Gang Up. Basically, if a bunch of monsters attack the same thing, instead of rolling each attack separately, every monster past the first one is treated as an instance of The Upper Hand, and a single Attack roll is made. This means if 4 monsters attack you in melee and there's no mitigating factor, you're automatically hit regardless of how much armor you're wearing.

I really like this rule. I also like how there's a "Horde Killer" Advancement specifically for countering this Gang Up tactic, and that this section points players to it. I would rule that non-identical monsters can gang up though.

Unconsciousness, Death, and Finishing Him!

Damage is deducted from a creature's Vigour score. If a monster/NPC reaches 0 Vigour, it dies. If a PC reaches 0 Vigour, they immediately flip a coin. Tails, they die. If they survive, they're Unconscious for 1d6 hours.

A monster can spend its action to "Finish Him!", i.e. kill an Unconscious character without rolling. The monster doesn't have to be in the same Zone or use a melee attack, though I'd only have a monster Finish Him! at range if I'd established them as being dangerous at that range. A dragon might barbecue a fallen PC, a tarantula-man might fire a volley of hairs, but a troll isn't going to suddenly whip out a sling.

There's no rule for nonlethal damage/subduing a monster. Decide how you want to handle this, because odds are the PCs will want to interrogate a shadow cultist at some point.

Heroic Rescues

Finishing Him! can only be blocked if another character performs a Heroic Rescue. The rescuer can't be further than 1 Zone away, and must make a Wit Check to leave a monster's Zone, as normal. The intent of this rule is unclear and could use. I assume it happens outside of initiative order, interrupting the monster's turn, with the rescuer forgoing their next turn? And can the rescuer jump in to, say, block the monster's attack with their shield, thus staying in the same Zone and avoiding the Wit check? Or is it only meant to be dragging your ally to safety, i.e. there's no way to avoid the Wit check?

Regaining Consciousness

A character recovers from unconsciousness with 1 point of Vigour, but can spend Grip 1-for-1 (up to 6), to wake up with more. Given how hard it is to regain Grip, I don't see players doing this much?

They also wake with one random Injury and one random Madness.

Exertion

You can spend Grip to reroll dice after seeing their results, but before the GM narrates what happens. You can reroll multiple dice in a roll (1 Grip point per die) but you can't reroll the same die multiple times.
You can do this for any roll you make, or for attack rolls an opponent makes against you. So obviously it covers Stat Checks and Attack rolls, and I assume Lay on Hands, but does it cover Initiative rolls or the coin-flip to see if you die upon reaching 0 Vigour?

Grip Checks

These are special Will checks the GM might call for whenever a PC encounters a terrifying, sanity-warping monster, environment, or event. Success on this check earns 1 XP. Failure causes loss of Grip, usually 1 point, but possibly more.

Resting

You can regain Vigour by resting. The amount regained is GM-determined, with suggested amounts depending on quality of food and shelter. I really like this over a more static amount, e.g. the 1d3 healing per full day of rest in BX D&D.

You only recover Grip by resting if it's in a tavern or settlement away from the dungeon, and even then, slowly if at all. The main way to recover Grip is by voluntarily taking Consequences (Injuries, Insanities, or if playing with the forthcoming Deluxe rules, Corruptions).

The text suggests that if the "main" party members head back to town to recover Grip, the focus of play doesn't follow them. Instead, continue the dungeoncrawl with backup characters from the same expedition camp. I like this. The players presumably signed up for the dungeoncrawl experience over a broader urban/wilderness game, so going back to town is for wusses.

Levelling Up

It's totally up to the GM when XP gets awarded, and how much, with only the "1 XP for every successful Grip check" rule being a firm guideline. Other suggested times are overcoming obstacles, surviving combats, and recovering treasure. 8 XP = 1 level.

Whenever you level up, you get +1 Vigour, +1 Grip, and choose an Advancement.

Status Conditions and Weird Rules

These rules cover various edge cases: being blinded, deafened, restrained or immobilised, darkness, encumbrance, drowning/suffocating, falling, starvation/thirst, climbing/swimming/crawling, and overland travel. They're all pretty straightforward. 

Encumbrance is left to common sense, exceeding it will probably slow a character or impose Against the Odds for some checks. I know the OSR stresses inventory management, but I don't think that necessarily means strict encumbrance rules. If you prefer more rigid rules, you probably already have a subsystem in mind. Personally, I'd crib from Knave and give each character inventory slots equal to 10 + Brawn.

20 Pieces of (Hopefully) Strange Dungeon Decor

The goal of this list is to be weird, sometimes ominous, but not immediately hazardous.

I'd use this to provide tangible hints of a room's history (or perhaps at what the whole dungeon was originally built for) and overlay a "what the current faction uses this room for " table.

1. Ancient scorch marks and glassed rock surfaces. Whatever took place here weakened the barrier between worlds. During an eclipse, the barrier weakens further, and the various dungeon factions will temporarily truce and set up market here to trade with extraplanar visitors.
   
2. A copse of transparent-needled pine trees, growing in an unseeable light. Spending significant time here (e.g. camping overnight) runs the risk of radiation poisoning.
3. Scrawled-on parchment scraps joined by red twine are affixed to every square foot of wall. A player can pose a question about the dungeon and have their character spend 2 turns (20 minutes) sorting through these notes for a 1-in-6 chance of a correct answer, and a 1-in-6 chance of an erroneous answer.
   The author's bones, picked clean by flesh-eating beetles, lie in a crevasse elsewhere. If his journal is recovered the odds of a correct answer increase to 4-in-6. The walls hold enough information to answer six questions, however long that takes.
4. A ghostly ecosystem drifts through the room. It contains 1 metre wide, 10 metre long jellyfish, small fish, miniscule zooplankton, and bacteria visible only as a shimmering ghost-sediment. At present, they are intangible and harmless.
5. A clockwork well constantly generating a lot of noise. If cranked, it will dispense precisely 1 litre of water. If oiled, will generate much less noise for about a week.
6. Metal filings cover the floor. They stand on end, and are repelled by iron or steel.
7. A tiled pool filled with tepid, shin-high water that is potable and magically self-cleaning. Dungeon monsters bring their toddlers here for swimming lessons.
8. Detailed, life-size origami effigies of the player characters stand in the centre of the room. Pulling a lever on the wall will cause the effigies to refold into whatever creatures will next walk into the room. Creatures who are aware of this mechanism's existence become immune to its powers.
9. Yellowed, curling WW2 propaganda-style posters warning denizens to be ever-vigilant of water weirds (or some other "trap" monster).
10. Twenty meathooks holding clay sculptures of animal carcasses. Some are realistic, some abstract, some naïve.
11. A stream of ants marching between two crevices, carrying thin scraps of gold leaf (1,000 scraps = 1 gp) from some unseen treasure vault to another unseen room where the ants farm their gold-metabolising fungus.
12. An automatic tapestry loom dominates the room. It slowly, in real time, documents the history of the local surface-world lords above. Go on, cut a thread in active use, just try it.
13. Crystal egrets fish in a lake of unknown clear liquid (harmlessly passes unabsorbed through the system of any human who drinks it). If exposed to sunlight, the egrets will grow sickly and crumble to dust in the course of a few days.
14. This room has no flat surfaces, and is really a void in an irregular packing of chrome spheres of various sizes. Each sphere is worth its weight in silver, but may cause a cave-in if shifted.
15. A low ceiling covered in cloth sharply transitions some 40 ft into the room to a much higher ceiling out of view. The low-ceiling area is littered with human-size mousie toys.
16. Prominent stone wall, carved with a phylogenetic tree of all demihuman and humanoid species known to the characters, plus several unknown ones. This might be multiple trees if the setting history doesn't have descent from a common ancestor. One entry is chiseled out, but the stone is extremely hard and resists common hand-tools.
17. A nanosun about 1 metre in diameter hovers in the centre of this roughly spherical room. It provides bright reddish light, local antigravity (one can walk anywhere on the sphere's interior), and the occasional lashing streamer of solar wind.
18. Huge excavated tree roots with taps installed -- the sap is delicious and nourishing, but pleasantly dulls perception and is partly antimagic. Drinkers are resistant to spells (including beneficial ones) and have difficulty casting spells, these effect scales with dosage.
19. Immobile electrical apparatus fills most of the room, with a prominent terminal featuring numbered dials and a gramophone horn. Racks of large carved stone ears line the walls, each ear is 2 metres long and carved with a serial number. Dialing a number into the apparatus lets you listen through the corresponding ear over any distance.
    A random number has a 1 in 6 chance of connecting to one of the ears in the room, a 1 in 6 chance of connecting to an ear in some random nearby location, and a 4-in-6 chance of being an unassigned number, connecting to a buried ear, or being otherwise useless.
20. This whole room is a time-capsule buried by child godlings, It features 20 ft tall trading cards, an enormous packet of expired gum that now only grants *delusions* of godhood if eaten, amber marbles with humans imprisoned inside, and a really interesting stick. Disembodied choral harmonies are faintly audible at all times. Reading the cards' divine language aloud risks wild magic effects.
    The really interesting stick is quarterstaff-sized, and can be brandished as an action to transfix all creatures within 30 ft of you. A Paralyse/Petrify or Wisdom save negates the effect, which otherwise functions as Hypnotic Pattern (see the Illusionist spell in AD&D 1e or OSRIC, or the D&D 5e spell). The stick isn't magical. It's just really interesting.

5 Old-School Spell Variants

This was prompted by discussion between @jellymuppet, @stratometaship, and @mountain_foot about whether spell variants are better written up as their own self-contained statblock, or as more terse, indicative notes that instruct the reader to refer to the base spell.


From that came these two blog posts

http://soulmuppet.blogspot.com/2018/12/some-variant-spells.html
https://footofthemountainadventures.blogspot.com/2018/12/spell-variations_4.html

so I felt inspired to write up my own.

At first I thought an advantage of the latter approach is that it's more resilient to the subtle differences between different old-school rulesets and their retroclones. For example, is a combat round 10 seconds or a minute? Does Magic Missile produce just 1 missile, or scale as the caster gains levels? Does armor class ascend or descend, and does it start at 9 or 10?

So I decided to write a few. And now I'm... less sure about which approach I prefer? I don't know if this attempt at edition agnosticism has worked.

Also, because it turns out lots of my favourite spells actually date to second edition AD&D. Since retroclones of that are rarer, I decided to provide notes on how those spells function anyway. Go figure. ;-)

 

Eyeball Torpedoes (Magic-User 1)

As Magic Missile, except the missile(s) are hovering eyeballs that swim through the air like tadpoles. They rupture on impact, releasing acidic humours.

When a caster prepares this spell, the appropriate number of eyeballs rapidly grow like enormous boils in a random location on their skin. Until fired, the caster can see through them. Once fired, the skin lesion left behind fades after 1d6 days.

 

Magical Transformation (Magic-User 2)

as Armor (i.e. mage armor in later editions), except:
 ●    it is a 2nd level spell
 ●    the armor is a visible costume change
 ●    it sheds light equivalent to a torch in the colour of the caster's choosing
 ●    it grants advantage on the first Charisma-based check the target makes during the spell's duration. If this is a reaction roll made on 2d6, instead roll 3d6 and use the best two.
 ●    the target can produce up to 20 ft of ribbons (as silk rope) at will. Reusing this ability causes previously produced ribbons to vanish.

In AD&D 2e, Armor affects one touched creature and has a casting time of 1 minute. It provides protection equivalent to scale armor (AC 6), which stacks with Dexterity and shield bonuses, but not the shield spell. The duration is indefinite, but the armor is dispelled once the wearer takes cumulative damage equal to 9 + 1 per level of the caster.

 

Alter Metabolism (Magic-User 2)

As Alter Self, but causes internal, physiological changes only. A nonexhaustive list of possible effects follows. These are not intended to be balanced against each other, and it is the GM's discretion as to whether two or more effects might be possible with a single casting.

Effects without a duration use the standard duration of Alter Self. In AD&D 2e, this is 3d4 minutes + 2 minutes per level.

 ●    Water breathing. You do not grow gills, but your lungs can extract oxygen more efficiently.
 ●    Altered skin pigmentation. This is an exception to the rule that changes are not generally visible externally.
 ●    Acclimation to high altitudes.
 ●    Unharmed by nonmagical extreme temperatures.
 ●    Improved poison and radiation tolerance. You have advantage on saving throws and/or halve any damage taken.
 ●    Suppress disease symptoms and infectivity. The disease resumes its natural course after the spell ends.
 ●    Hibernate for 1 month. During this time, you can only be roused if you take hit point damage.
 ●    Safely digest organic material such as carrion, wood, peat for 1 day.

 

Consult the Elements (Cleric 2)

As Augury, except the caster's question regarding a course of action is answered by local elemental spirits. The possible answers are Earth, Fire, Air, Water, Balance, or an appropriate cryptic phrase. The answer might be literal or be more metaphorical. For example if the question is "What awaits us on the third level?", an answer of "Water", could mean dank, flooded corridors, a faction of crabfolk, or a cool dispassionate sphinx who vivisects adventurers that cannot answer her riddle.

In AD&D 2e, Augury takes 2 minutes to cast, and must relate to a course of action taken in the next 30 minutes. The base chance of receiving a meaningful reply is 70% + 1% per level of the caster.

Element    Qualities        Humoural Disposition
Earth      Cold and Dry     Melancholic (sad, pensive)
Fire       Hot and Dry      Choleric (bad-tempered, irritable)
Air        Hot and Moist    Sanguine (optimistic, positive)
Water      Cold and Moist   Phlegmatic (calm, stolid)

 

Cloth to Chiropterans, a.k.a Brocade to Bats (Cleric 4)

As Sticks to Snakes, except it turns 4d8 square feet of cloth, leather, or other textile into that many normal bats. Note as they are under the caster's control, they do not have to make morale checks every round.




If this targets textiles worn or carried by another creature, that creature is entitled to a save vs paralysis/petrify to avoid the effect.

There is a 1 in 6 chance the bats carry disease.

Stats below are from B/X Essentials: Monsters
 
Normal Bat
AC 6, HD 1hp, Att 1 × swarm (confusion), THAC0 20, MV 9’ (3’) / 120’ (40’) flying, SV D14 W15 P16 B17 S18 (NH), ML 6, AL Neutral
 ●    Swarm: 10 bats can swarm around a character’s head, causing confusion: -2 to hit rolls and saving throws; unable to cast spells.
 ●    Attacks: As normal human.
 ●    Flighty: Unless magically summoned or controlled, normal bats check morale every round.