ALCHEMY! A system for weird experiments

An alchemy system, written for this month's RPG Blog Carnival!

The following tables present a subsystem for alchemy in OSR games, taking LotFP as the base (so, all prices are in silver standard – if your game uses gold standard, just replace “sp” with “gp”). For Laboratories, see LotFP: Rules & Magic, p. 82-83.

The system is intentionally convoluted and baroque. Like any good old alchemy, it is untested, volatile, and unpredictable! Use it as written, or just steal ideas from it, as usual! Have fun!

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Opera

The cornerstone of alchemy is the opus (plural: opera), the “work”. Essentially, an opus is like a recipe, a detailed notation of an alchemical process.

Mechanically, opera are recorded as sequences of dice rolls. Note the type of dice and the result for each step of the workflow. This is important, because later on the Alchemist has the opportunity to recreate or modify existing opera. Opera stolen or obtained from other Alchemists can be deciphered.

Each opus also has a separate rating, from 1 to 6, which measures how well the Alchemist who created it mastered the alchemical process.

Alchemy skill

The Alchemy skill is rated from 0 to 6. Any character can learn it in-game. The LotFP Specialist class can assign skill points to it during character generation.

For all Alchemical activities, a Laboratory worth at least 1000 sp is required.

The maximum number of activities that can run in parallel in a single Laboratory depend on the physical size of the facility: 1 activity for every ten 10’ squares the facility occupies (regardless of value).

Chart of substances

This are the substances that can be used as the base substance for Alchemical activities. They are measured in alchemical units.

Exact measurements can be calculated like this: 1 alchemical unit of clay weighs 1 pound; 1 alchemical unit of a more valuable substance weighs 1 pound divided by the price of the substance. E.g. 1 alchemical unit of silver (30 sp) weighs 1/30 pound. Sorry, this is super wonky and might not make much sense.

Number	Substance	Price of one alchemical unit
0 or less	Useless slug	0 cp
1	Clay	1 cp
2	Chalk	1 cp
3	Turpentine	5 cp
4	Salt	5 cp
5	Potash	1 sp
6	Saltpeter	3 sp
7	Copper	5 sp
8	Sulfur	5 sp
9	Iron	10 sp
10	Tin	10 sp
11	Quicksilver (mercury)	15 sp
12	Zinc	15 sp
13	Arsenic	15 sp
14	Glass	15 sp
15	Plumbago (graphite)	20 sp
16	Lead	25 sp
17	Silver	30 sp
18	Electrum	50 sp
19	Gold	100 sp
20	Platinum	200 sp
21 or more	“Unobtanium”	? sp

Alchemical activities

Pick the type of activity, the opus (if such exists), and the base material (see Chart of substance above).

Alchemical activities	Time required	Disaster check
Experiment	1 week of work* + the duration of the process	Yes
Execute opus	1 day of work* + the duration of the opus	Yes; modified by the rating of the opus
Perfect procedure	1 day of work* + the duration of the opus	Yes; modified by the rating of the opus
Modify opus	1 day of work* + the duration of the opus	Yes; modified by the rating of the opus
Combine opera	Duration of the longer opus	Yes
Decipher unfamiliar opus	1 week of work*	Yes

* Work = uninterrupted time spent at the Laboratory

After that, the duration of the opus can go on unsupervised.

Duration of the opus

The amount of time required for the alchemical process to complete. The Referee rolls 2d4 twice to learn the duration but tells the Alchemist only the Time unit (e.g. “it will take any number of weeks).

Roll	Number	Time unit
2	1	Round
3	3	Turn
4	6	Hour
5	7	Day
6	9	Week
7	12	Month
8	13	Year

Interruption

If the Alchemist doesn’t want to wait for the process to complete, they can interrupt it. Roll a Disaster check.

Disaster check

Save versus Magical Devices. The save might be modified by the rating of the opus (check the Alchemical activities table).

• On a success, the Laboratory loses 1d20 x 100 sp in value, but nothing extreme happens.
• On a failure, waste of supplies and accidents reduce the value of the Laboratory by 2d20 x 100 sp. On a natural 1, there is a dangerous explosion which destroys 5d20 x 1000 sp of the Laboratory’s value and the Alchemist (and also the Apprentice, if present) suffers 1d10 damage (save versus Breath for half). [Disaster rules based on LotFP: Rules & Magic, p. 83]

Activity: Experiment

If the work is done and the duration of the process is left to complete, make an Alchemy check:

Alchemy check

Target number. Sum up the total of the following factors. Some factors have a maximum possible bonus they can grant.

Factor	Bonus	Maximum bonus
Alchemy skill*	= skill rating	-
Class: Magic-User, Cleric	+1/every 3 levels	+6
Working with existing opus	= opus rating	-
Value of Laboratory	+1/1000 sp	+9
Value of Library	+1/1000 sp	+7
10/100/1000 units of the base substance	+1/+2/+3	+3
Intelligence	= Ability modifier	-
Wisdom	= Ability modifier	-
1/2/3 Apprentices**	+3/+4/+5	+5
Extra work time invested	+1/week	+3

* A character without the Alchemy skill takes a -10 penalty on this roll.

** If the experiment is a success, roll a Loyalty check for each Apprentice. A disloyal student might run off with their master’s opus or equipment.

*** Collaboration. A maximum of two characters (not counting Apprentices) can collaborate on one work. One character is chosen as the lead. The second character’s bonuses are counted, but are capped at +6.

Then roll a d20.

• If the result is less than or equal to the target number, the activity is a success. Roll up a random Result for the experiment! Roll a Disaster check.
• If the activity is a success AND the roll result is less than half of the target number, the Alchemist manages to record the procedure correctly and adds it to their opera. From here on, they can execute, perfect or modify this opus. Roll up a random Result for the experiment, record every roll made on the subtables. The Alchemist now knows the exact Duration of the opus. Roll a d4 to establish the starting rating of the opus. Roll a Disaster check.
• If the result is more than the target number, the experiment is a failure, the time and work and materials are wasted. Roll a Disaster check.

Activity: Execute opus

Same as an Experiment, but add the rating of the opus to the Alchemy check; and instead of a random result, success on the Alchemy check re-creates the opus as recorded.

Activity: Perfect opus

After 1 week of uninterrupted work, roll 1d6. If the result is equal to or larger than the current rating of the opus, add 1 to the rating of the opus.

Activity: Modify opus

One single parameter recorded in the opus can be modified (usually this means a new roll on a random table). The following parameters can be modified: Duration, Result*, any subtable or random roll related to the Result.

* The Result itself can only be modified if the initial Result of the recorded opus was in the 1-4 range on the d20.

Activity: Decipher opus

Decipherment of an opus never recreated the result, but makes it known to the Alchemist. Make a Disaster roll.

Results

Roll 1d20, then see below for details!

1-4	No result; but if the opus is recorded, it can be modified (see Alchemical activities) and the Result re-rolled
5-7	Change in appearance
8-10	Change in quality
11-12	Change in quantity
13-14	Glow
15-16	Magnetism
17	Radiation
18	Absorb energy
19	Transform energy
20	True transmutation

Change in appearance

Roll 1d5.

1	Looks like different substance (“fool’s gold”), roll 1d20 on the Chart of Substances
2	Color change (roll 1d20 on the Carcosa color chart, re-roll results above 13: 1 black, 2 blue, 3 bone, 4 brown, 5 dolm, 6 green, 7 jale, 8 orange, 9 purple, 10 red, 11 ulfire, 12 white, 13 yellow)
3	Transparency (roll 1d6, where 1 is just slightly transparent and 6 is almost invisible)
4	Reflectiveness (roll 1d6, where 1 gives a dim silhouette and 6 is brighter than the brightest mirror known to mankind)
5	Change of texture

Change in quality

Roll 1d8. If the substance already has this or a similar quality, double the intensity.

1	Flexible
2	Stretchable
3	Malleable
4	Rigid
5	Durable
6	Extremely durable
7	Fragile
8	Extremely fragile (if broken, everyone in 5’ must save against Breath or take 1d6 damage)

Change in quantity

Increase/decrease. The substance grows or shrinks quantitatively, without changing any inherent qualities. Roll 1d6 (shrink or grow?) and 1d8 to see how many units remain from the amount that went into the experiment. Fractions are lost.

Þ1d8      1d6Ü	1-3 (Shrink)	4-6 (Grow)
1-3	1/10	2x
4-5	1/5	3x
6-7	1/3	5x
8	½	10x

Glow

The substance emits light. Roll 1d6 four times on the following table:

Roll	Distance	Intensity	Character	Duration
1	5’	Phosphorescent	Flickering	1 turn
2	10’	As candle	Flickering	1 hour
3	15’	As torch	Constant	1 day
4	20’	As lantern	Constant	1 month
5	25’	As lantern	Slow pulse from dark to maximum intensity	1 year
6	30’	Blinding	Stroboscopic	Forever

Magnetism

Pulls metallic objects from 1d4 x 5’, with an intensity of 3d10 – at least this amount of combined Strength is needed to resist to magnetic pull and this is the maximum weight in it can attract per pound of magnetic material. E.g. one unit of magnetized substance with an intensity of 21 can pull 21 units of iron, characters with a combined Strength of 21 or more can hold back against it.

Radiation

Living creatures in vicinity of the radioactive substance must save against Poison or take 1 damage; roll 1d10 to see how often: 1-5 once per day, 6-7 once per hour, 8-9 once per turn, 10 once per round.

Absorb energy

Roll 1d10 for the type of energy the substance absorbs (see Energy type in “Transform Energy”). Roll 1d10 for “storage capacity”: this is the abstract amount of energy the substance can store. This might mean that it can absorb heat (e.g. from a fire) for 1d10 rounds, or absorb impact (e.g. from a weapon hit) worth 1d10 damage. See the entry for Transform energy for ideas on what happens when the substance “overloads”.

Transform energy

The substance can now transform of one type of energy to a different type of energy. 

Roll 1d10 twice. The first roll shows which type of energy the substance absorbs (optional: roll 1d10 for “storage capacity” as well, see the entry for Absorb energy). The second roll shows which type of energy it releases instead. Then roll 2d3 for intensity modifier (it is up to the Referee to decide what the “release of four times more magical energy than the heat absorbed” might mean, sorry… Maybe 4 random magic missiles for each 5 damage the heat would potentially do?). Optionally, roll 2d3 for release delay (the amount of time that passes between the absorption and release of energies).

1-3	Impact
4-5	Heat
6	Magnetism/electricity/lightning
7	Sound
8	Light
9	Magical energy
10	Thoughts

Intensity modifier, roll 2d3:

2	¼
3	½
4	roughly equal
5	2x
6	4x

Release delay, roll 2d3:

2	1d6 days
3	1d6 turns
4	1d6 rounds
5	Instantaneous
6	on trigger: roll 1d10 on the Energy type table to see what is the trigger

True transmutation

This is it. The opus magnum. The transmutation of one substance into another. The exchange rate is one unit to one unit. No loss, no gain. Roll 1d20, then subtract 1d10 from the result. Record this final number (which might be negative). Take this number of “steps” on the chart of substances, beginning from the initial substance of the experiment.

Examples: The Alchemist uses Salt (4) as the initial substance. 

Situation #1: The d20 comes up as 8, the d10 comes up as 5, totaling to 3. Salt is transmuted into 4+3=7, that is Copper. The same opus, if successfully recorded, would turn Lead (16) into Gold (19). 

Situation #2: The d20 comes up as 5, the d10 comes up as 9, totaling to -4. Salt is transmuted into 4+(-4)=0, that is, Useless slug…

Zero or less is always Useless slug. 

21 or more, on the other hand, creates an extremely rare and valuable substance inherent to your setting, or even a radically new substance that doesn’t otherwise exist in nature.