1d8 pools of the old Faith

1. 

MERE. Surrounded by gnarled oaks where that teem with maggots like old wounds is a mere. A tall knight, Meryld of Merrow, stands to her knees in the oily water, methodically throwing an anchor-like hook to drag the dark pond. On the shores lie a diverse array of bones and bent metal already exhumed, giving off an unpleasant smell as it dries.

The knight is courteous, but very preoccupied with her task as she is convinced that a Drune witch is working curses from under the surface. In a nearby camp are three local youngsters, tending to her equipment and sifling through the debris caught in the pond each afternoon.

If the knight's trust is won, she tells that she travelled with Raillarde the Paynim to the Druids many miles west of Alverdis, but that they parted ways. She fears that the fellow knight has come under a spell, and believes the witch she seeks is its cause.

Any character scouting the area can pick up tracks of heavily burdened steel boots, leading north towards the shore.

2.

MENHIRS. Several menhirs stand by a small pool, only a few paces wide. Sleeping among them grants vision of grieving woman, fleeing across a landscape of endless darkness. If a character spends more than one night by the menhir, the woman will recognize them them from the night before and speak to them in hushed and hasted voice: begging to be freed, warning of the pursuing monster, and the cruel knight Wilkin that keeps her trapped. The woman does not know where she is, only that it is dark, and wet, and terrible, but she promises to call on the wind each night.

The woman is currently in a pool by the standing stones of Corroc, but is moved by her jealous guardian each new moon. Any character who has spoken to her can hear her voice on silent nights, and locate which direction it comes from with a successful WIS roll.

3.

EMPTIED TARN. Among the heaps of salvage decomposing on the shores of this tarn lies the reeking body of a large wyrm. The creature's head has been severed by a single strike, but the fat slugs feasting on the carcass still causes its body to oscillate in some deathless reflex. If searched, the salvage contains little of use.

4.

HERMIT. In a cliffside hut lives a naked hermit, surrounded by seabirds. She is reluctant to speak but can tell that her father was a squire to Knight Blaine the Recréant. If treated kindly, she offers an adder-stone that her father brought from Naoned Ker, after parting ways with the fallen knight.

Adder-stone. If worn as a ring, the bearer cannot be attacked by spirits and spectral beings on a successful save and suffers only half damage from poison. On a natural 1, however, the stone shatters.

5.

GLEAMING POOL. Gold gleams from under the surface of this wide pool, like the lure of a trap waiting to be sprung. The pool is surprisingly deep, and the gleam is lost underwater but if the gold is retreived it turns out to be an eyeless helm carrying the face of a newborn.
Dawn helm: AR 2 (Magic 4). The wearer can reduce SPI by one to have the helm shine like the sun for an hour.

6.

PETROGLYPH LAKE. In the middle of a large mire where leafless trees claw at the sky is a small lake, about a bow-shot across. In its midst is a large rock with a single pine, its roots firmly clutching the stone to reach the water below. Between them are hints of petroglyphs, signalling that this place was once of great significance and perhaps is still, for worn ribbons fly from the trunk of the solitary tree.

The lake is haunted by bog-men, who attack at night or during overcast days.
BOGMEN (2d6): HD 4, AR 3 (Magic 4), bronze curveblades (1d6+1d6 magic, brittle: shatters on a natural 1).
+ Loses 1 HD at the beginning of each turn spent above the surface
+ Regains 1 HD for each turn spent submerged
+ Moves through water and mire like it was not difficult terrain

If the petroglyphs are cleared, any character studying them closely can make a WIS roll to understand that they detail sacred rites that can be performed here to gain a spell. Performing the rite takes a full month, after which the character can cast a single spell while standing on the rock, or suffer one permanent wound to memorize it forever.

7.

WYVERN POOL. In this opaque pool lives a Wyvern, poisoning its water and killing those drinking from it.
WYVERN: Huge, HD 5, AR 4, MV 5 (walk/fly/swim), claws: 1d8 (piercing, target it thrown 1d10 squares in random direction) + bite: 1d8 (piercing, poisonous: suffer 1d4 damage per round until aided or successful save).
+ Mesmerizing song: Each 1d4 ronuds, save or be paralyzed until aided.

8.

DEATH KNIGHT CAIRN. A wet trail of mud and molten leaves lead towards a moss-covered cairn, where a death knight sits singing a mournful song by a pool of stale water.

WILKIN OF MONBELAC: Large, HD 7/7, AR 5 (chain +1, poison 6), MV 4, Giant flail (dmg 2d8, knockback, reach 2, area, deathblow)
A knight in ancient armour, dark with rust and dripping with water, carrying a drowned woman on his back and a faint lantern in his belt.

+ Hail of blows: Whenever a character comes within 2" in front of Wilkin, they must evade or be struck by an automatic hit by his flail.
+ Life drain: any character immediately behind the knight must evade or be clasped by the woman on his back, suffering 1d4 poison damage per round and being paralysed until a successful save.
+ Unnatural life: Wilkin has two HD pools. When one pool is reduced to zero Wilkin is downed. Any surplus damage is lost, and all ongoing effects targeting him ends. If for any reason his lantern is put out, he loses 1 HD per round and the woman takes no hostile actions.
+ Return to the water (when downed): When the first HD pool is reduced to 0, Wilkin begins crawling toward the stale pool to gently place his cargo in it. After this, he gains a bonus attack and a free movement each round and the woman fights as a separate character.

DROWNED WOMAN: HD 1, AR 1 (Poison 10), MV 2, corrputing word (dmg 1d12, range, poison: target's skin bisters and rot like old fruits)

Timers

1d4 rounds: Curse. Wilkin lifts his lantern, and the drowned woman lifts her head in great pain and vomits forth a black tangle of seaweed and writhing eels with a terrible scream.
EELS (2d4 tangles): small, HD 0 (2 hp), MV 1d4" random direction, bite (1 dmg poison damage, no armour).

Encounter: The Siege of Luthria

This is a decent siege encounter that can be placed basically anywhere as long as you have a wall-encosed location with few soldiers except the PCs. As written, it was prompted by a chance encounter with a Kvaner host when returning to the place that is now the PCs base of operations - hence the strong assumptions about timing and intent. In most other cases, you shouldn't preclude the options of parlaying, surrendering, etc. However, you can probably still use this encounter as a blueprint for enemy tactics, when and if they decide to attack.

**

A Kvaner host has returned to lay waste to Luthria, flags cracking like dissonant marching drums in the gale. A single braying horn at dusk announces their attack, and arrows start hailing down like the wet, storm-slung snow.

SETUP
Place enemy miniatures and allow the players 10 minutes of planning, positioning, etc. Then the attack begins. For building details, see Luthria convent.

TARGET: 12 / 15 (light/dark).
Map is dark, unless as arranged by the PCs.

ARCHERS (3x10): HD 1 (1hp), AR 2 (leather), bow 1d6 (half armour) or daggers 1d6.
+ Fire as one: each unit fights as one and rolls a single attack roll. The attack roll has +1 to hit per unit member alive, and deals +1 damage per 2 unit members alive.

SOLDIERS (12): HD 2, AR 3 (rusty chain), shield: 1d6 + axe: 1d8
+ Batter: each round at least 4 soldiers are by the gate, they swing the battering ram for 1d12 damage against the gate.

COMMANDER VASIL: Mounted, HD 4, AR 4 (chain), poleaxe 1d12

RIDERS (2): Mounted, HD 2, AR 2 (leather), poleaxe 1d12

SCOUT: HD 2, AR 1 (helm), shield: 1d6 + sword: 1d6
+ Agile: evades at +5.

LAYFOLK: HD 0 (6hp), AR 1 (miscellaneous), club or bow 1d6

NUNS: Will not partake in fighting, but may help with first aid, keeping lookout, putting out fires, etc.

SPECIAL RULES
+ The gate can withstand 20 damage from the battering ram.
+ Indirect fire: each round, everyone inside the convent has a
3/100 risk of being hit by indirect arrows for 1d6 damage.
+ Spotter: Each 1d3 rounds, a spotter climbs a random
unmanned tower. As long as the spy is alive, the risk
from indirect fire increases to 1/10
for all characters within the spotter’s line of sight.

+ The attackers retreat when 4 or less soldiers remain. 

Eight shrines

1    Ashwold

South of Tinslay is a tall square building of uneven rocks, veiled by spider web that extends in long white tresses to the surrounding trees and over the ground. A withered statue of great age rise out of the web; its pedestal bears the arrow-like mark of the Consolers and a nigh-unintelligible inscription reading DICIO * SATOR. Inside lives a great spider, tending to six large egg sacs of dense web that slowly moves. Denser patches of spider web on the grond cover six pit traps; if a character walks on them, they fall into the pit and lose their remaining movement. When they emerge, 1d4 young spiders follow.
GREAT SPIDER: Large (1d8), HD 4+2, AR 2, MV 6, dmg 1d6 + poison.
+ Climb: Each 1d8 turns, the spider leaps up in the ceiling, tree, or web; there it remains until it suffers damage, spraying a noxious acid at its turn (dmg 1d6, ranged, 3" area, everyone hit must save or armour is dented).
+ Poison: if at least 1 point of damage goes through armour, the target must save or suffer 1d4 damage/round until successfully treated
+ Erratic movement: if attacked and missed, the spider immediately moves 1d6" in a random direction.

YOUNG SPIDER: Small (-1d8), HD 1, MV 9, dmg 1d6 + poison.
+ Poison: if at least 1 point of damage goes through armour, the target must save or suffer 1d4 damage/round until successfully treated
+ Spider sense: the spider can evade any number of attacks and makes evade rolls at +6.

Egg sacs

1:    Corpse of a man, wearing a deep red robe. When opened, 1d4 young spiders crawl out from the sac each round until it is completely destroyed. The dead man has almost no nose and appears to have been an itinerant merchant of some sort, for with him is a wide array of pouches and goods. Most is now useless, but two firebombs, 1d10 pieces of glimmering red gold, and a parchment scroll. The parchment is badly damaged, but if carefully restored it contains a clue.
2-5:     wild animal, barely alive and crawling with spiderlings - when opened, all adjacent characters must evade or suffer a -3 penalty to all actions for the next round as their skin crawls with countless spiderlings. The dying animal has 1 HP and will move 1d4" in a random direction each round until dead. As long as it is alive, all adjacent characters suffer the -3 penalty.
6:    ragged man, alive but severely disfigured by the spiderlings feeding from him - when opened, all characters within line of sight must roll INT or be SHAKEN. The man is disoriented from the spider's poison but if saved, he turns out to be a local farmer who briefly travelled with Raillarde the Paynim as a guide. After a bandit ambush - which he had nothing to do with, he swears - he fled and never saw the knight again. Last he know, the knight was headed north, towards Belmyre.

2    Loudreác

Nine nine miles east of King's road is a small stone shrine, adorned with imagery of queen Aelwydd and surrounded by a low wall that is dwarfed by thistles and shrubbery. The wall is partly destroyed by the encroaching forest, but curiously has no visible gate. A statue of a old woman lies toppled among the weeds, its head missing. The inscription reads: GENTRX * CELSUS * NOSTER.
Inside sits a knight, motionless and reclining against the wall. If approached, the knight comes to life.
GODRYDD THE ACCURSED: HD 5, AR 6, Shield (1d8), MV 6, dmg 1d8+1d6 (longsword)

3    Langonne

An old chapel, slowly keeling into a dark pond. The chapel is adorned by the the tear-shaped mark of the Consolers, but the scarred oak trees surrounding the pond speak of ceremonies still older. If there ever was a statue or idol, it is long since lost. Inside the dark chapel lies a mummified arm in a monstrance, black like tar and smelling of rancid apples.
HAUNT: HD 2, AR 0, MV 5, dmg 1d8 magic
+ Deathless: The haunt is immune to all physical damage, but is immediately vanquished if its relic is destroyed.

4    Orvault

On a small island in a reed-covered lake are the ruins of a shrine, dwarfed by a cairn that better withstood the test of time.  The island is home to a band of goblins, whose cooing calls can be heard across the lake. Using sleds and snow-shoes of twigs, the light goblins can move through the dense reeds without getting wet; for everyone else, the reeds counts as difficult terrain. A great lamprey lives in the lake, feeding of animals that get stuck in the mud, and the goblins are careful to move quickly across the reeds and stay away from any open water.
GOBLINS (3d6): small (-1d8), HD 1, AR 2, mv 6, dmg 1d6 (bows: ranged, poison arrows - save or DOWNED) or 1d6 (spears).
+ Pack tactics: Ignores size penalty if outnumbering target

GIANT LAMPREY: HD 4, AR 0, MV 8/4 in reeds, dmg 1d4 + grapple
+ Motion sense: The lamprey relies on motion to find its prey; each round not in melee, it prioritizes moving towards the largest splash or disturbance of the water surface, then the nearest, or else moves at random. It will only attack characters or creatures that are in the water.
+ Grapple: A target successfully grappled by the lamprey is pulled under water, where they suffer 1d4 fatigue per round from asphyxiation.
+ Submerged: The lamprey only rises from the water to attack, otherwise its position is only revealed by the parting reeds. When submerged, the lamprey is in full cover to all but adjacent characters.

5    Egwyn Fach

A sturdy shrine built from neatly-fitted and perfectly square stones sits untouched by time among elderflower trees and rows of salsnip. A pathway lead across the garden to the shrine, each of its of white stones carrying a brown mark looking like a cloven hoof. Inside the floor is covered by hay and fragrant branches. Here lives a peaceful hermit Eroästes and his sheep, collecting wild flowers to adorn a large statue of the God Mother. The hermit speaks only sparingly, but is otherwise happy to help. He knows medicine and has a few books; if studied, one of them provides a clue.

6    Soudan

A walled-up cave by a small stream forms an inconspicuous shrine, built at the foot of a long path leading up a steep hill. A nearby stone reads FARAN - AELWYDD THEODCWEN - BYLDED - CIRCE. Inside the shrine is a travelling merchant.

7    Derrill

By a swampy pond leaking into the Wallingwall channel is a wormstung timber shrine. Inside, the floor stones form the tear-shaped mark of the Consolers. The nun Odille is resting inside; fleeing from Whitesun she is terrified of man-masked demons, but is friendly if convinced that the PCs are mortals.

 8    Pyworth.

A turret-like shrine, walled by several low rows of standing stones. Outside the perimeter of the stones is an encampment, flying the flag of Tuillote of Haute-Occ. His retinue is currently tending to the badly wounded knight and several graves give testimony to recent casualties.

Inside the shrine, stone stairs leads down into a vast, dark chamber where the Foot of the Bleeder is kept. Here resides Lantern Knight Gwent, the formidable foe who has so ravaged the noble knight outside.
TUILLOTE (wounded): HD 2 (fights as HD 5), AR 6, Shield (1d10), MV 6, dmg 1d14 + 1d4 magic (spear called Segwryck) or 1d8 (sword).
RETINUE (2d4): HD 2, AR 4, Shield (1d6), MV 6, dmg 1d10 (axes)

1d6 graves of fallen knights

1.

A large rock, overgrown with ferns. Crushed underneath are the remains of a nameless Knight. The troll that hurled the rock still lairs nearby; ancient and wicked she carries the skull of the dead knight on her club, occasionally swearing at it or ridiculing it.
HAG-TROLL: Huge (2d8), HD 6, AR 3, dmg 1d12 (gt club: knockback, area) or 1d12 (boulder: ranged, 2x2 square area)

+ Mesmerizing song: Each 1d8 turns, save or be paralysed.
+ Regenerates 1HD per round. Immune to magic.

2.

The pine-forest here is quiet, and bones litter the ground. Among the lichen-covered trees lie a heap of toppled stones - all that remain of the once-splendid grave of Byrla the Shield. Each night the dead knight returns to cursed life, intent only on killing. If vanquished, the knight begins hauting again at the next full moon unless the body is placed in hallow soil.
CURSED KNIGHT: HD 5, AR 4, Shield 1d16 (3), dmg 1d8 + 1d6 magic (cursed sword).

+ Unhallowed charge: Each 1d4 rounds, the knight charges 2d4 squares forward and attacks with an impaling strike: target must save or suffer 1d12 magical damage and lose 1d4 Spirit.
+ Fay Shield: The Fay Shield of Byrla protects against all types of damage, and reflects the damage back at the attacker if the shield roll is higher than the damage roll. If taken from Byrla, it breaks and withers on a roll of 1.
+ Cursed: Cannot cross running water, must return to corpse at daybreak.

3.

A solemn stone of pink granite marks the grave of Brathos of Werelden. The inscriptions read "As in life, so in death." A large family of wild boars have partly exhumed the bones through extensive burrowing; curse-stricken, they now hunt for food. The boars secrete a dark oil that turn their manes into porcupine-like quills, and gradually kills the forest surrounding their lair. On the week of a full moon, there is a 1-in-4 chance that Gloso is among them.
QUILLED BOAR (3d4): HD 2, AR 2, MV 9, dmg 2d6
Charge, knock down, disengage

+ Bristles: when evading an attack, the boar deals 1d6 damage to the attacker
+ Death struggle: when reaching 0 hp, the boar immediately makes a melee attack before dropping dead.

GLOSO: Large (1d8), HD 6, AR 4, MV 9, dmg 2d8
Charge, knock down, disengage

+ Poisonous exhale: Each 1d4 rounds, Gloso exhales a cloud of black smoke covering 1d8x1d8 squares. The cloud obscures line-of-sight and dissipates at a rate of 1 square in each direction per round. Everyone in the cloud must save or suffer 1d6 poison damage (no armour).
+ Bristles: when evading an attack, Gloso deals 1d6 damage to the attacker
+ Death struggle: Each 2 HD lost, Gloso immediately makes a melee attack.

4.

A great heap of branches and fallen trees adorned with feathers mark the nest of a huge bear-like creature. Beaked and feathered like an owl, it hunts mainly at night and is at disadvantage in direct sunlight. Tangled in the roots in one of the storm-felled trees are broken human bones, barely held together by fragments of green fabric with gold-tread inlay. This is the remains of a nameless knight. If investigated, a sword can be retrieved from the light-brown soil (as longsword; crit on a 19-20).
OWLBEAST: Large (1d8) HD 4, AR 4, MV 6, dmg 1d8 + knockback (area) or 2d6 + grapple

+ Pounce: Each 1d8 turns, the Owlbeast leaps forward 2d4 squares. All PCs in its path must evade or be pushed forward and suffer 1d6 damage (half protection from armour) as they are crushed under the terrible weight of the landing beast. In addition, the Owlbeast may make a single melee attack with its beak upon landing, dealing 2d6 damage (rending: armour reduced by 1).

5.

In the flooded ruins of a small stone temple lives a tribe of leech-skinned goblins. Inside the temple is the remains of Sir Folming; mummified in the marsh, the goblins have exhumed the body and distorted it into an grim idol.
LEECH-GOBLINS (3d6): Small (-1d8), HD 1, AR 4, mv 6, dmg 1d6 (spear).

+ Pack tactics: Ignores size penalty if outnumbering target
+ Impossible to shake: The goblins gain a +3 bonus to grappling; when the grappling goblin is removed, the grappled character suffers 1d3 damage for each failed attempt to break free from it.

GOBLIN LEADER: Small (-1d8), HD 4, AR 4, Shield 1d4(2), mv 6
dmg 1d8 +1d4 magical (sword)

+ Command: Each 1d8 turns, the leader issues an order and the other goblins must immediately charge towards a target or hurl their spears at a specific target. All goblins must follow the same order, towards the same target.
+ Spear of Folming: the leader uses the head of the mummified knight's spear as a sword. If repaired into a spear, its damage increases to 1d10 + 1d6 magical but any failed attempt will dent the weapon.

6.

The wind carries the sweet fragrance from a glade where butterflies swarm over ever-flowering thorns. In the middle of the glade lies the remains of sir Heaved, peacefully as if resting. If the body is removed, the glade will slowly die but similar flowering thorn-bushes will sprout forth over the course of 1d6 days from all dead matter the body touches until it is placed in hallowed soil.

Sample potions

The feasibility of the sub-system for Alchemy I proposed for the alchemy month hinges on the presence of multiple formulas for the same potion. Only by finding two or more formulas that creates similar effects will players have a chance to understand the principles of correspondence and substitution. The presence of multiple formulas also reinforces the notion that formulas are more like recipes for cooking than chemical notation; or that they consist of equal measures fluff and crunch.

To better show what I mean, I've made a small pdf containing three variations on a potion of restoration, and three variations on a potion of healing. While they are designed with this system in mind, you can also use them as stand-alone handouts if you just want to award your players with a tangible representation of their scroll or similar.

Rules for Alchemy

Apparently, there is an alchemy month going on. That's neat, since I've been thinking a lot about alchemy now that my campaign is on pause. Here are my rules. They are not at all playtested, but at least in theory I'm really happy with them.

The basic idea is that alchemy should be about formulas, trial and error. The system therefore makes a strong distinction between simple player-facing rules which are basically "say a prayer, and follow the formula" and more involved referee-facing rules which governs how formulas should be designed. For most players, alchemy is consequently about finding a formula and questing to retrieve the ingredients. For those who want, however, alchemy instead is about trying to understand what makes the potion effective, and/or trying to improve it.

Hopefully, you can find some ideas worth stealing. An example formula can be found here; and there is plenty of inspiration for more over at Slugs and Silver.

A system for Alchemy

PLAYER-FACING RULES

Alchemy is a craft based on a secret system of mystical correspondence. To create an alchemical potion, your character needs
- A formula
- The required ingredients
- Paraphernalia and tools

Any character possessing these things can be an alchemist. To become a master requires understanding the correspondences that govern all of creation - a task that may easily consume a lifetime.

Preparing a potion

Before preparing a potion, alchemists commonly fast, say a prayer or invocation that will compensate for their impending blasphemy. Failure to take proper precautions results in minor corruption (-1 Spirit).

After these precautions, just follow the formula.

Determining the Effect of a Potion

The potion's effect is determined by three things
- The formula
- The alchemist's INT
- How closely the formula was followed

When the potion is used, or otherwise tested, roll d20 and add INT of the character preparing the potion to determine its quality.
Formula was followed exactly
- the potion always has effect
- failed INT-roll means side effect: minor corruption (-1 Spirit)
- natural 1 means side effect: major corruption (-1d4 Spirit)
- natural 20 means potion not depleted; it was so effective it can be used again

Minor deviation from the formula- the potion only has effect on successful INT-roll

Major deviation means the potion never has effect.

Creating new formulas

If a process involving minor deviations is successful, it can be codified into a new formula. Once codified, it is no longer considered a minor deviation for rules purposes. To codify the process, the player simply writes it down.

Prepared potions

A prepared alchemical potion should be noted as
"Potion of healing (minor, +3)"
indicating the formula used, how closely the formula was followed, and the INT of the alchemist.


 REFEREE FACING RULES BELOW

REFEREE FACING RULES

For referees only, below image.

The Formulas

There are three basic types of alchemical formula:
- Pure
- Diluted
- True
When designing formulas, you start with the Pure.

The Alchemical Principles

To design the formula, you first decide what class of potion it will result in.

There are four alchemical Principles, or classes of potions, corresponding to a colour each. All potions use a base that is determined by their principle. They are
- White (purify, heal): White wine, distilled alcohol, fermented milk, or other white/clear liquid intoxicant
- Yellow (enhance): Ale, Mead, or other yellow/golden liquid intoxicant
- Red (alter): Red wine, or other red liquid intoxicant
- Black (?): Ichor

A healing potion will thus be white, a potion of giant strength yellow, and a potion of growth red. The black are there as a possibility; not currently part of my campaign.

The Pure formula

The Pure formula consists of 5 components
1 base- An intoxicating liquid of a colour determined by the Principle of the potion.

3 ingredients
- A natural ingredient (something from nature)
- An unnatural ingredient (something made)
- A preternatural ingredient (something with magical or mystical properties)

1 reagent- Salt or potash gives a normal potion
- Sulphur gives a weak potion (+3 to INT roll)
- Mercury gives a strong potion (-3 to INT roll)

Diluted formulas

Over time, many formulas become diluted when passed from Alchemist to Alchemist, or developed from flawed understanding of the pure process. A diluted formula has the same effect as a Pure formula, but contains more than the 5 required ingredients. These additional ingredients may give side effects, but are commonly just cosmetic. For example: an alchemist may decide to add honey to a potion where honey is not required, just because they prefer the taste or to see if a rival alchemist is stealing their formula (and thus also including the unnecessary honey).

Using a diluted formula means characters have to collect more ingredients, but otherwise carries no penalties.

True formulas

Through clever substitution (see below), it may theoretically be possible to create a formula with less than 5 components. The hypothetical formula using the least number of components to create an effect are known among alchemists as True formulas.

Substitution

Alchemy works through correspondence. Thus, all components can be substituted with another component of sufficent similarity. For example, red wine may be substituted as a base by blood and white wine, and a hippogrif egg might perhaps be substituted by the egg of an eagle raised among horses. Substitutions like these are considered a minor deviation.

If a substitution is successful (meaning: the character succeeds with the INT roll to determine the potion's effect), the character can codify the process as a new formula. In game, this is done by a player writing down the process. Through iterative attempts of substitution and codified processes, a clever alchemist might eventually arrive at a formula that is very different from the original.

A Potion to Restore Life