The exact function of laboratories, rare materials, and formulas, as well as how the system works when two or more alchemists cooperate, is not yet written. Players start with the ability to make the alchemical items in the book (listed below) without the need for a formula. If they
receive a formula for one of those items, it would in some way modify the four qualities during the end step. Other formulas do not modify the qualities, but give the alchemist access to more production options. Materials are probably spent during an action, rather than during the end step, but I don't have a better sense of how that works yet.
I've written this on the theory that I'd be able to modify it for other crafting skills and research actions as well, but that's work for another day, I'm afraid. Unsurprisingly, everything here is phrased for use with D&D Next, but my guess is that it wouldn't take more than minor adjustments to bolt it onto 3.x and 4e.
This alchemical crafting system is based on improving two
positive qualities while minimizing two negative qualities. There is a fifth
quality that provides a necessary endpoint to the work. This makes for a
variety of data tracking, but gives the system considerable nuance. There are a
number of other moving parts in the system as well, obscuring the chance to
solve the game.
The five qualities are Intensity, Quantity,
Volatility, Cost, and Time. Once Time runs out, the player applies values from
any end-step modifiers, such as formulas, laboratories, assistants, or rare
materials. I've assumed that a single unit of Time is about two hours, and a character cannot work for more than eight hours in a day. If it's important to you that completing alchemical production take more in-game time - and there are plenty of good reasons you might hold this position - then change Time to four hours, one day, or whatever suits you. The consequences of Volatility and Fate mean that alchemists may well need to take up to a week off between Alchemy challenges just to recuperate.
determines the level of the item the alchemist makes – whether the alchemist’s
fire is the most basic variety or the dreaded alchemist’s hellfire
. Intensity does not decrease during the end
step. Increasing Intensity inevitably increases Cost and Volatility. It is deliberately difficult to drive this value very high, though there will certainly be items that have an almost unreachably high Intensity.
determines how many uses of the various items the alchemist can make. This is
the positive quality that the alchemist spends during the end step; the
alchemist is not required to take this number to zero.
determines the number of unexpected outcomes that the alchemist generates.
Volatility adds directly to Fate rolls made during the production process, and
any Volatility that remains during the end step must be resolved with rolls on
a separate Volatility table. The Volatility table may apply temporary disadvantages
to the alchemist, cause specific products to be highly unstable, or cause them
to have unexpected effects when they are used. Volatility can
benefit the alchemist, and no one ever advanced the study of
alchemy without taking some risks with high Volatility.
Cost is a value
multiplied by 1/10th of the market value of all of the alchemical
items you created in your working. Even failed rolls increase Cost by a small
amount; only Fate can reduce Cost prior to the end step, and such outcomes are
very rare. If you end an alchemy challenge with a positive Cost value but elect
not to spend any Quantity, you pay 1 gold coin per point of Cost (materials
spent, and cleanup costs).
The player influences these qualities with four different actions,
and each action consumes a variable amount of time. Unless otherwise specified,
all rolls are Intelligence checks to which Alchemy applies. All actions except
for Rubedo (the end step) trigger a Fate roll upon completion. For actual play, I intend to work on improving the formatting of this information.
Base DC 14 yields +1 Intensity. Every additional 5 points of
the check result yields an additional point of Intensity. You may double the
Intensity points yielded by this roll at a cost of +2 Volatility and +2 Cost.
Special: If you already have a positive Intensity value, this
action is at disadvantage. The second and all later rolls made when you have a
positive Intensity value suffer disadvantage that cannot be canceled.
Alternately, you may pay 2 Cost and discard all previously accrued Intensity.
Base DC 17 yields -1 Volatility. Every additional 5 points
of the check result reduces Volatility by an additional point. This action has
a base +2 Cost.
Failure: Reduce any beneficial stat by 2 or increase any
negative stat by 2.
Base DC 14 yields +1 Quantity. Every additional 5 points of
the check result yields an additional point of Quantity. This action has a base
DC 21: Reduce any negative quality by 1 or increase any
positive quality by 1.
Research (DC determined by project): +1 research point. Add
your Volatility score to this check.
Special: This action does not trigger a Fate roll (since it
usually requires one or more rolls on the Volatility table). During this
action, you may spend Quantity on items of up to your Intensity value. Multiply
your Cost score by 1/10th
the market price of each item you make;
this is your material cost (the rulebook typically expresses this in gold
coins). You must
roll on the Volatility table until you reduce your Volatility quality to 0 or less.
Note: the Volatility Table and the Fate Table are intended to be changed up every few sessions. The only consistent point to them is that low rolls are mostly more desirable than high rolls.
(1d20 + current Volatility)
1-2: Toxic Gases. DC 12 Constitution save; on a failure,
take 1d10 poison damage. Reduce Volatility by 1.
3-6: Minor Explosion. DC 12 Dexterity save; on a failure,
take 1d10+2 fire and acid damage. Reduce Volatility by 1.
7-8: Strange Fumes: Suffer disadvantage on all Charisma
checks for 1d6+1 days. Reduce Volatility by 1.
9-12: Disease-laden Vapors: Suffer disadvantage on all
Constitution saves for 1d6+1 days. Reduce Volatility by 2.
13-16: Destructive Explosion. DC 12 Intelligence save; on a
failure, your lab requires repairs worth at least 50 gold coins before it can
be used again. Reduce Volatility by 3.
17-18: Odd Malfunction. DC 12 Intelligence save; on a
failure, your most powerful creation from this span of work malfunctions when
used. This malfunction is typically minor. Reduce Volatility by 1.
19-20: Malaise. Suffer a -2 to all weapon and magic attacks
for 1d6+1 days. Reduce Volatility by 3.
21-22: Coughing Fit. Uncontrollable coughing causes you to
fail all Stealth checks for 1d6+1 days or until you receive a disease-curing effect.
(Medicine-related check DC 15.) Reduce Volatility by 3.
23: Unexpected Insight! Gain +1 research point to your
current research project, if any. Increase Volatility by 1.
24+: Big Boom! One alchemical item in your possession is
destroyed, chosen randomly. Reduce Volatility by 3.
Fate Table (1d20 + relevant modifiers)
1 or less: Quick Work. Your next Time roll is minimized. Add
+1d6 to the next Fate roll.
2: Inspiration. Your next Alchemy roll gains advantage. Add
+1d6 to the next Fate roll.
3: Job Well Done. Gain +1 Intensity.
4: Job Well Done. Gain +1 Quantity.
5: Stable Formulation. Reduce Volatility by 1.
6: Minor Setback. Reduce Intensity by 1.
7: Minor Setback. Reduce Quantity by 1.
8-9: Minor Setback. Increase Cost by 2.
10: Efficient Work. Decrease Cost by 1.
11: Unstable Formulation. Increase Volatility by 2.
12: Tension Increases. Add +1d6 to the next Fate roll.
13: Incredible Breakthrough. Gain +1 research point to your
current research project, if any. Ignore this result if it occurs twice in a
single Alchemy challenge.
14: Magical Interference. You are immune to magical healing
for 1d3 days.
15: Destructive Explosion. DC 12 Int save; on a failure,
your lab (if any) requires repairs worth at least 25 gold coins before it can
be used again. Ignore this result if it occurs twice in a single Alchemy
16: Magical Intensification. Your Hit Die values for healing
are maximized for 1d6+1 days.
17: Temporary Physical Refinement. Suffer disadvantage on
all Intelligence checks and saves for 3 days, but gain advantage on all
Strength checks and saves. Increase Volatility by 2.
18: You’ve Been Cheated. One of your rare material
components (determined randomly, if any) turns out to have no potency.
19: Powerful Component. One of your rare material components
(determined randomly, if any) turns out to have an extra beneficial effect.
20: Damn the Neighbors! Your work suffers an interruption;
make a DC 14 skill check relevant to the nature of the interruption or lose 1d4
Time. (Persuade or Intimidate are often useful here.)
21: Vagaries of Fate. One of your formulas (determined
randomly, if any) is damaged to the point of illegibility. Reduce Volatility by
22: Mental Fog. DC 14 Constitution save; on a failure,
suffer disadvantage to all Intelligence and Wisdom checks and saves for one
23: Dangerous Explosion. DC 14 Dexterity save; on a failure,
suffer 2d8+4 fire and acid damage. Reduce Volatility by 2.
24: Acid-Walker. You gain resistance to acid damage for 1d4
days. Increase Volatility by 2.
25+: Big Boom! One alchemical item in your possession is
destroyed, chosen randomly. Reduce Volatility by 3. Reduce the next Fate roll by 1d6.
Basic Production List
(no formula required)
Alchemist’s Fire, 50 gp, Intensity 2
Antitoxin, 50 gp, Intensity 2
Healer’s Kit, 5 gp, Intensity 1
Basic Poison, 100 gp, Intensity 3
Potion of Healing, 50 gp, Intensity 4