Creating alchemical effects
It is the GM’s job to determine what alchemical effects each creature can confer.
Not every monster produces potions and oils and bombs. Sometimes a creature might only be able to produce a potion. Tell players this up front when they harvest a creature’s reagents.
For creatures included in Appendix C, the GM’s task is relatively straightforward. We’ve included example substances for these monsters below.
For creatures of the GM’s own invention, a little thought and inventiveness is needed.
Some advice for GMs:
Steal the creature’s powers
When an adventurer harvests reagents, look at the creature’s stats and choose a few greater dooms that seem relevant and easy to convert for an adventurer’s benefit.
If the creature has an essential gimmick, it makes sense to include that gimmick as a potion. Example: A mermaid’s spleen can yield a potion of waterbreathing.
Potions might also provide a meaningful defense against a monster’s essential gimmick. Example: A medusa’s snakes can yield a potion that makes the drinker immune to petrification for a watch.
Does the monster have a signature attack? Seems like a good mechanic to tie to a bomb. Example: A dragon’s gallstone can yield a bomb that creates a fiery blast with the Critical effect.
Alchemy only lasts for a watch
Generally, a substance’s effect only lasts for a watch—no longer. Unless an effect is minor or restores a natural state, it will eventually wear off.
Disregard balance, embrace creativity
“Encounter balance” is not a meaningful concept in His Majesty the Worm.
If the players manage to defeat a strong creature, part of the reward is to gain strong alchemy from its corpse.
Because alchemical substances are single-use items, powerful effects are a fun lark and have little longterm effect on a game.
Keep good ideas, discard the rest
When inventing alchemical effects, write out all of your ideas. Sift through them. Delete the ones that don’t seem to work. Keep the ones that do.
Some monsters will produce identical effects. That’s okay.
Some monsters will produce almost identical effects but a little bit better. That’s okay too.
What do players know about alchemy?
The GM should not tell players what alchemical effects can be obtained from a monster until they brew alchemy. The mystery is part of the fun.
Can a player read this chapter and get a sense of the alchemical substances derived from the creatures in Appendix C? Of course. They can read a book. We’re not cops.
Reading this book still does not reveal the alchemical effects for monsters that the GM invents themselves.
There are two exceptions:
- Bidding lore: If an adventurer has a pertinent motif (e.g., Big Nerd Alchemist or Wizened Dragon Eater), they may bid lore to ask about a particular monster’s alchemical substances.
Each lore bid is a single question. That is, each lore bid reveals a single way that a reagent may be brewed: what are the effects of this monster’s potion, what are the effects of this monster’s bomb, etc.
- Rumor mill: Discovery is fun, pretending that you don’t know something isn’t. The rumor mill (Chapter 6: The Crawl Phase) ensures that players don’t have to spin their wheels discovering something twice. If a guild learns about the alchemical effects of X, Y, and Z, the rumor mill allows them act on that information in-character in the future. Even in this case, though, the GM isn’t the one revealing this information. The adventurers simply have a justification for knowing what they know outof-character. The players are responsible for tracking and remembering this information.