Thursday, 31 January 2019

Noisy Map Maker

I made a spreadsheet (it's a Google Sheet) that takes a dungeon map like this one:

gridded dungeon map to be transformed by various rules
Raw map data

...and turns it into an imperfect, noisy dungeon map handout for your players. Naturally there's lots of ways to introduce noise/errors to an image, but I wanted one that was solveable by clever players. That is, it'd still have some use if they couldn't solve the puzzle, but if they could, they'd know the dungeon layout.

(in this case, not the presence of doors or walls dividing adjacent rooms, as the map scale is 10 ft per cell. But you could make a map to a different scale)

How it works is by assigning a random number from one of two lists to a cell, based on whether the corresponding cell for the true map is blank or not. The two lists follow / don't follow a simple mathematical rule. Then a simple conditional formatting rule fills the cell based on whether the number is above a certain threshold. The conditional formatting creates the "noise", while cracking the rule gets you back to the true underlying information.

The easiest version of this puzzle just uses two adjacent sets of integers. You can even let players have control over the conditional formatting if a laptop or tablet is available, letting them home in on the correct threshold:

gridded dungeon map with adjacent-intervals rule applied
Numbers in [0,255] / Numbers in [256,512]

A simple divisibility rule is of middling difficulty.

gridded dungeon map with divisible-by-3 rule applied
Divisible by 3 / Not divisible by 3

Probably the hardest of the three pre-populated options is prime numbers. Though if you used this one, you could be sneaky here and indicate secret doors or similar with a 1, as 1 is neither prime nor composite.

gridded dungeon map with prime-number rule applied
Composite numbers / Prime numbers

You can download and mess around with the sheet, defining your own number lists (and associated rule to crack) and tweaking the conditional formatting threshold to have the right amount of noise. If you use this in a game, let me know how it goes!

Just remember the two lists must have different averages, otherwise the conditional formatting applied to the cells won't tell players much. A list of the first 1,000 even numbers and the first 1,000 odd numbers will look completely random if the conditional formatting rule is "colour cells with value > 1000". The goal is to look sufficiently nonrandom so as to tip off the players there's actual meaning to decipher.

But diegetically, what is this handout anyway?
d6 Reason for the map
1. An ancient alien scannerbot, caked with dust, has done a geophysical survey of the dungeon. Its memory is corrupted, but its hologram display function still works. The map is unlikely to include recent dungeon extensions or geologic shifts.
2. A room has a huge crystal, glowing amber, set in the ceiling. Dust motes hover in the light, apparently trying to tell you something. They respond to your thoughts more than they do drafts of air, their motion growing less random the more you concentrate. In this case the numbers aren't literal, decoding them represents this concentration.
3. Extremely paranoid da Vinci-type gnome was the dungeon mapper for an adventuring party, disguising her findings as apparent gibberish numbers. Her skeleton lies in a trapped secret corridor, her cipher too devious for her party to decipher and come to her aid. Her worldly possessions, including the journal with this map, are for sale at an auction.
4. An imp bound in chains of rock-salt sits impudently in a glowing magic circle. Eager to tempt the party into a dark deal he quickly pens the map in immaculate calligraphy for them. He promises them the trick to reading it, if only they would release him.
5. Each number is actually meaningful. An ethereal telepath-spider unable to sense the physical world made the map to chart what it perceived as the dungeon layout. The map is a hovering blue tapestry, that can only be manipulated by ghosts and force effects. The dungeon is enchanted such that if two creature stand in spots with the same number, they can see through eah other's eyes and telepathically communicate. There is no saving throw to resist this effect, but moving to a different spot breaks the link.
6. A colossal brain-eating catfish lurks in a cavern behind a secret passage. They have seeded the dungeon with clues, in the hopes of luring only the most intelligent, piquant brains to their demesne.

Tuesday, 29 January 2019

Reincarnated Background (5e)

You died.

The druid brought you back. You are now something else.

The druid won't say why they did it, or what they want in return. They left a token behind. You tried throwing it away, but it always returned the next day.

"You are free to continue your mortal life", they told you. Druids always lie.

Note that choosing this background does not mean you have to roll on a reincarnation table for your former or current race. Two tables are provided below, the standard table, and a spicy table. Consult your GM about which to use if you decide to roll.

Proficiencies and Equipment

As another background (choose or roll), plus one of the following trinkets left to you by the druid.


  1. pendant carved from oak, stylised weeping eye
  2. tiny smooth riverstone knife, grip shaped for no human hand
  3. owl skull, glimmer of starlight in its orbits
  4. hybrid flower, dried/pressed between two sheets of giants' fingernail
  5. wax anticandle, grows taller and sheds darkness when burned
  6. fairy-chess piece, imparts intuitive sense of its legal movement to all who touch it

Feature: Agent of The Druid

You understand Druidic, but cannot speak it.

The druid reincarnated you for a reason they chose not to share with you at this time. They exist as a patron who may offer additional favours or call in their debt.

You are also notable within druid circles, apart from the most remote or isolationist ones. Revealing your benefactor's sigil may open certain doors, but it may also attract unwanted attention.

Ideals, Bonds, Flaws

Use another background's tables for these. Your reincarnation has not changed these.

How You Feel About Your Reincarnation

  1. Ill-fitted. Phantom limbs, itching sensations, clumsiness with your new proportions.
  2. Alienation. Accepted neither by your old race or your new one.
  3. Gratitude. The possibility of redressing past regrettable actions.
  4. Freedom. To live a new life unshackled by your old reputation and actions.
  5. Fish out of water. People react to your new identity, affording different privileges, trust, or fear.
  6. Absolutely nothing. The mortal body is false and transitory, the spirit is the true reality. So nothing's really changed, right?
  7. Relief.. You were dragged out of Hell. You probably fear returning.
  8. Grief. You were dragged out of Heaven. You probably hate the druid's guts.
Standard Reincarnation Table
d100 Race
01-04 Dragonborn
05-13 Dwarf, hill
14-21 Dwarf, mountain
22-25 Elf, dark
26-34 Elf, high
35-42 Elf, wood
43-46 Gnome, forest
47-52 Gnome, rock
53-56 Half-elf
57-60 Half-orc
61-68 Halfling, lightfoot
69-76 Halfling, stout
77-96 Human
97-00 Tiefling

For the following, spicier table, roll a d6 twice (i.e. d36) for uniform odds, or d100 for odds closer to a typical fantasy setting.

Note that a GM who prefers a less kitchen-sink setting should curate their own table, or let player rolls on this table determine which intelligent nonhumans exist or are predominant within the setting.

Spicy Reincarnation Table
d36 d100 Race
1-1 00-01 Aasimar
1-2 02-03 Aranea
1-3 04 Azer
1-4 05-06 Crabfolk
1-5 07 Dragon (wyrmling, random colour1)
1-6 08-10 Dragonborn
2-1 11-16 Dwarf
2-2 17-21 Elf
2-3 22-24 Fir Bolg
2-4 25 Flumph
2-5 26 Garuda
2-6 27-31 Gnoll
3-1 32-35 Gnome
3-2 36-43 Goblin
3-3 44 Golem (clay)
3-4 45 Gwyllion
3-5 46-53 Halfling
3-6 54-55 Houri
4-1 56-65 Human
4-2 66-67 Jinn
4-3 68 Kappa
4-4 69 Kitsune
4-5 70-73 Kobold
4-6 74-76 Lizardfolk
5-1 77 Maenad
5-2 78 Mantisman
5-3 79-80 Merfolk
5-4 81 Naiad
5-5 82 Nāga
5-6 83-88 Orc
6-1 89 Sahuagin
6-2 90-91 Selkie
6-3 92-93 Slugfolk
6-4 94 Tanuki
6-5 95-98 Tiefling
6-6 99 Yakfolk
1Roll d10 and read across: black, blue, brass, bronze, copper, gold, green, red, silver, white

Sunday, 27 January 2019

Intangible Resources, a houserule for Knave

This is adapted from Throne of Salt's rules for Backgrounds. It's written for Knave, but is easily applicable for D&D.

A knave might have knowledge or social standing that they accrued before they join the campaign. These rules are intended for open-world, sandbox game with significant time spent in settlements. But in the event your dungeoncrawl one-shot spins off into a longer campaign, you can always go back and generate these resources for whichever knaves survive.

Generating a Knave's Resources

  1. Add together your knave's Int, Wis, and Cha bonuses.

  2. Roll that many d6. For every natural 1, put a point in Authority. For every natural 2, put a point in Renown, and so on.

  3. Further increases or losses will come about as appropriate during gameplay.

Resource Roll Table
Die Result Resource Type
1. Authority - Influence within regions/social spheres where you have political power. May let you requisition resources, get better treatment from officials, etc.
2. Reputation - As Authority, but where you don't have direct political power.
3. Languages - Can you communicate with the goblins without resorting to pantomime? Can you decipher the ancient scroll? Can you understand the metaphor behind the sphinx's literary references?
4. Secrets - Knowing the truth behind the curtain.
5. Lore - Knowing the location of a forgotten temple, the properties of a legendary magic item.
6. Divine Favour - Are you in good stead with the gods? Will they pull your arse out of the fire when your plan goes to shit?

e.g. Susan rolls up a new knave, getting Int +1, Wis +2, Cha +1. She then rolls four d6, and gets 1, 1, 6, 1. She notes an Authority score of 3, and a Divine Favour score of 1.

Susan decides her knave is the bastard daughter of the local lord. She cannot inherit title (hence turning to adventuring) but has almost as much social standing as a trueborn daughter would. She prays regularly but isn't particularly pious.

Using Resources

Some possibilities:

  1. Roll-Under for Success. Roll a d6 when you want to draw on a resource. A roll equal or below your rating is a success.

  2. Burn a Point for Success. You cannot roll, the only way to draw on these resources is to permanently cross off a point.

  3. Burn a Point for Advantage. Permanently cross off a point to gain advantage on an ability score roll. You can retroactively use this on a roll you have failed.

  4. Roll Under or Burn. Roll a d6, as with variant 1. If the roll fails, you may decide to succeed anyway by burning a point, as with variant 2.

The referee should decide on one of the above variants, or mix and match depending on situation and the risks/rewards.

e.g. you might decide that "the cheesemonger is having an affair with the town priest" is a pretty mundane secret, knowable with a d6-roll-under against Secrets. The True Name of a vengeful river spirit is a much more valuable secret that may require burning a point.


  • How long is this planned campaign? If it's only a few sessions, then perma-burning points may not be a meaningful resource.
  • Are the players comfortable with the added complexity of remembering that ability score rolls are roll-high on d20 while want a high roll on a d20 while resource rolls are roll-low on d6?
  • How often do you want players to solve problems with resources, compared with equipment or spells? Variant 4 is relatively powerful, and shifts the game to be more about managing social connections.
  • How cool are you with a character who rolls a lot of one Resource effectively having a monopoly on that roll until they die or do something within the game fiction that reduces it? Requiring characters to burn Resource points is more likely to let everyone contribute.
  • Depleting Resources eventually means characters will need to adventure specifically to regain social capital.

Note that adding Resources to the game should never take away the ability of any knave to bribe the town guards, find information in a library, or any other action resolvable with an ability score roll. Ability scores are, after all, king.

Thursday, 3 January 2019

Opossum (BX Class)

I remembered Grant Howitt's Trashkin existed partway through writing this. I've tried to make sure content in this is useable in that game, and vice versa.


You had a good life. Rustled through some garbage, raised a litter of thirteen hissing young, the humans mostly left you alone. At the ripe old age of two, you were ready to die.

But something happened. Maybe it was that weird-coloured tick you ate. Maybe it was the goo seeping from the walls of your burrow. Whatever cause it, you began to change.

Now with two opposable thumbs and the intellect of the humans you once feared, you set out to plunder the undisturbed trash of long-forgotten tombs.

Hit Die: d6
Save as: Dwarf/Halfling
Attack as: Magic-User
XP progression: Magic-User
(see end of post for the level progression table)

Combat. Opossums are unable to wear any kind of armour, but may use a shield. They may use any weapon appropriate to a creature of their tiny size. As a guideline, they must wield any melee weapon with a 1d6 damage die in two hands, and cannot wield melee weapons with a larger damage die. They can wield all missile weapons except for longbows.

Bin Wizardry. An opossum can cast spells. See the BIN WIZARDRY rules below.

Play Possum. If a monster/NPC attack takes an opossum below half their full HP, this ability triggers automatically. The opossum becomes comatose for 1d6 x 10 minutes, and secretes fluids that make them noxious and unpalatable to eat, except to a carrion-eater. A save vs. paralysis avoids this effect, if desired.

Prehensile Tail. Opossums can carry (but not wield) objects in their tail, or use them to aid climbing. They can climb sheer surfaces as well as a thief of their level.

Reaching 9th Level. When a opossum attains level 9, they can establish a stronghold, usually in a run-down, abandoned manor, keep, or shrine. Other opossums will venture to this promised land, hoard their treasures within, and fortify it against intruders with makeshift traps. 1d6 of these opossums will be other uplifted ones, who will serve graciously as long as the Trashlord strings them along with promises of sharing their hard-won magical secrets.


A opossum starts with two random spells from the OPOSSUM SPELL TABLE. They don't learn new spells through level-up. They learn them via mishap results of 6 & 8, or by reverse-engineering another opossum's talismans.

Spells that affect a creature may be resisted with a save vs. spells, or other appropriate saving throw.

Each spell an opossum knows is bound in its own talisman. Roll on the TALISMAN FORM TABLE to determine its appearance. To cast a spell, an opossum needs that talisman on them, and a hand free (or holding the talisman if appropriate), but does not need to speak.

A opossum can cast each spell they know as often as they like until that spell misfires. Each time they cast a spell, roll a d20, trying to get equal-or-below their Intelligence score. A opossum casting a magic-user spell (i.e. one learned via a misfire result of 8) has a penalty to this roll equal to the spell's level.

Failure causes a misfire, meaning:

  • the spell doesn't go off
  • roll on the MISFIRE TABLE below
  • the talisman for casting that spell is broken until the opossum can repair it in a safe haven.


Misfire results of 6 and 8 cause a opossum to cast an unknown spell instead. Thereafter, the opossum can construct a talisman for that spell in a safe haven.


  1. gaudy bangle
  2. misshapen medallion
  3. fascinator/tiny hat
  4. wizard hat/top hat
  5. monocle (no lens)
  6. tiny ring of power
  7. special belt buckle
  8. bag of glitter
  9. knobbly stick
  10. cool crystal
  11. lucky bone
  12. crown cut from tin sheet, inlaid with coloured glass beads. Improve NPC reaction results by 1 step when dealing with other opossums


Note that results of 6 & 8 are the main ways an opossum learns new spells. If you want to use a different misfire table, consider tweaking it to keep a roughly 30% chance of this happening.

2d6 Misfire
2. 1d6 animals within 60 ft are UPLIFTED, much as you were.
3. The touch of your paws ignites flammable objects.
4. Spell affects all creatures within 60 ft, or conjures 10 times as many seagulls, 10 times as much mucus, etc.
5. Your fur turns a random colour of the rainbow (1d8, ROYGBIV order, an 8 means roll twice more). If shorn, grows back as its original colour.
6. Accidentally cast an opossum spell you don't know, determined randomly.
7. Prefix an O to one or more of your character's names. It is not silent.
8. Accidentally cast a true magic-user spell. Determine spell level by rolling 2d6 and using the lower die, then determine a random spell from that spell level's list.
9. A nonmagical item on your person breaks and becomes useless.
10. Magnetically attract all nearby trash and debris, some of it forms surprisingly functional armour. Roll 1d6 to determine your new AC, which lasts for 1 hour (6 turns). e.g. in a descending system with unarmoured AC 9, roll 1d6 + 2. In an ascending system with unarmored AC 10, roll 1d6+10. Make ability score adjustments as normal for your system.
11. Cycle denominations of all coins on your person. Roll a die. If odd, do this in an increasing direction i.e. CP -> SP -> EP -> GP -> PP -> CP. If even, do this in a decreasing direction.
12. Portals to THE PLANE OF TRASH open, dumping 4d6 cubic feet of assorted trash (poisonous if set aflame) plus one of the following (equal chance of each): 1d6 RUSTED LUNKERS who hunger for fresh metal, a wise and docile FATBERG, or the PLASTIC PRINCE, who loves nothing more than a devil's bargain.


  1. BIG EYEBALL. conjure 2-ft-diameter glass eye. Shatters after 1 hour. It cannot move of its own accord, but rolls quite nicely. You see through it until it breaks.

  2. BOUNCY BOI. Used in response to an attack that hits with kinetic force, e.g. a sword, a rolling boulder trap, but not poison darts or dragon breath. Take no damage, instead bounce around like a bouncyball. 2 in 6 chance of landing somewhere inconvenient.

  3. CARCASS TRIVIA. For 1 hour any corpse or remains you touch will stir to life and tell you one thing it knows. They will not stir again, even on a different casting of this spell.

  4. CONJURE SEAGULLS. Swarm of seagulls appears within 60 ft for 10 minutes. Distracting and utterly fearless. Surrounded creatures cannot cast spells. Will mob for food. You have no control over them.

  5. DELIGHTFUL SMELL. Detect presence and direction of any edible material within 60 ft. You cannot tell materials apart, they all smell delicious. This includes most monsters.

  6. EXCAVATE. For 10 minutes, can telekinetically excavate or tunnel through soil or other loose, packable material, at a rate of one 5-foot cube per minute. Excavation lasts 1d6 weeks before collapsing.

  7. MUCUS. Stick two things together, requires 2d6 total points of Str to pull apart, or pounds of force equal to 50 x that number. Can also plug leaks, prevent evaporation, etc.

  8. NEW TEETH. Creature touched grows a new set of teeth over 20 minutes. All old ones fall out over this time; quite painful.

  9. RENDER EDIBLE. Transmute 10 pounds of material into a substance rather like raw potato. Worth 2 days' rations, 4 if cooked.

  10. SCRËM. 60 ft range, creature affected must shout their next sentence. Lasts indefinitely until sentence is uttered. Generally audible to 300 ft. The creature can use this sentence to scrëmolocate, thus mapping all open passageways & terrain features within 120 ft, but not enclosed rooms or secret doors.

  11. SO DUSTY. 10 ft square area within 60 ft is covered with a thick layer of dust. Each breathing creature passing through area has a 2 in 6 chance of a horrible fit of sneezing.

  12. STILTWALK. Touched creature's legs grow by 15 ft. Gives enormous stride, increasing combat movement rate by 15 ft. Creature is ungainly, has disadvantage on rolls requiring nimbleness. Exploration movement rate is thus unaffected.


The following table is based on B/X values.

To-Hit lists two numbers, the first is THAC0, the second, [bracketed] value is for ascending systems, using the magic-user attack bonuses in Swords & Wizardry.

A unified save, also taken from S&W, is provided. If (and only if) this is used, a opossum receives +4 to saves vs disease and poison (and not the +4 vs magic that the dwarf and halfling receive).

A Google Sheet version of the following table can be found here

Opossum Level Progression
Level Title XP Hit Dice To-Hit Climb Sheer Surfaces Saving Throws
Unified Death Wands Paralysis Breath Spells
1st Waif 0 1d6 19 [+0] 87% 14 8 9 10 13 12
2nd Scrounger 2,500 2d6 19 [+0] 88% 13 8 9 10 13 12
3rd Degenerate 5,000 3d6 19 [+0] 89% 12 8 9 10 13 12
4th Mudlark 10,000 4d6 19 [+0] 90% 11 6 7 8 10 10
5th Guttersnipe 20,000 5d6 19 [+1] 91% 10 6 7 8 10 10
6th Tatterdemalion 40,000 6d6 17 [+1] 92% 9 6 7 8 10 10
7th Trickster 80,000 7d6 17 [+2] 93% 8 4 5 6 7 8
8th Mountebank 150,000 8d6 17 [+2] 94% 7 4 5 6 7 8
9th Trashlord 300,000 9d6 17 [+3] 95% 6 4 5 6 7 8
10th - 450,000 9d6+1 17 [+3] 96% 5 2 3 4 4 6
Hit point modifiers from CON no longer apply