The Manual Of Alchemy allows a Magic User or Thief to learn how to brew potions or perform a few other alchemical feats. To use the book, the character must study a page for at least 8 hours a day for a week. At the end of the week, he will know if he understands the recipe. If he does not, he can make another attempt by studying another week. Once known, he will understand the ingredients, implements and procedures for following the recipe. The book must be present and open to the correct page to attempt a brewing which takes 1d4 hours.
To succeed in brewing, you must roll d20 versus the recipe difficulty, adding any intelligence bonus. The DM rolls for success and checks a table for the result of failure if necessary. You don’t know if you’ve succeeded until you try the potion.
Brew Failure
| % | Result |
| 1-5 | Weak: the potion works as intended but all numeric effects are divided by 1d4. |
| 6-79 | No effect: the potion has no effects at all. |
| 80-85 | Intoxicating: you are incapacitated for 1d20 hours. |
| 86-90 | Poison: after 1d20 turns, save vs death. |
| 91-94 | Explosion: at completion, the potion explodes in a fireball for 4d6 damage. Save for half damage. |
| 95-98 | Different: you accidentally brewed a different potion. Determine randomly. |
| 99 | Opposite: the potion has the opposite of the intended effect. |
| 100 | Enhanced: actually, you made a potion that’s 1d10 times stronger. |
Recipe Difficulties
| Recipe | DC | Ingredients |
| Acid | 12 | Bile or stomach acid |
| Antitoxin | 10 | Snake venom |
| Clairaudience | 15 | Ears of any undead |
| Clairvoyance | 15 | Eyes of any undead |
| Cold Resistance | 16 | White dragon blood |
| Control Animal | 16 | Animal blood |
| Control Dragon | 20 | Dragon bile |
| Control Giant | 19 | Hair or Fingernail of giant or ogre |
| Control Human | 17 | Hair or Fingernail of human or demi-human, lotus pollen |
| Control Plant | 15 | Leaves, lotus pollen |
| Control Undead | 18 | Corpse dust, lotus pollen |
| Delusion | 15 | Lotus pollen |
| Diminution | 17 | Halfling blood |
| ESP | 16 | Human brain |
| Fire Bomb: self-igniting flask of oil | 10 | Oil, Fireweed |
| Fire Resistance | 16 | Red dragon blood |
| Flying | 18 | Roc feathers |
| Gaseous Form | 18 | Wraith dust |
| Giant Strength | 19 |
Hair or Fingernail of giant or ogre |
| Growth | 18 | Giant blood |
| Healing | 15 | Holy water, human blood |
| Heroism | 19 | Holy water, Dust of one large sapphire |
| Invisibility | 19 | Eye of any undead |
| Invulnerability | 20 | Dragon blood |
| Levitation | 16 | Shadow essence |
| Longevity | 15 | Elf heart |
| Oil of Slipperiness | 15 | Oil, Frog skin |
| Poison | 15 | Animal venom |
| Polymorph Self | 19 | Chameleon liver |
| Smoke Bomb | 10 | Oil, Fireweed |
| Speed | 18 | Giant shrew bile |
| Treasure Finding | 15 | Dwarf brain |
| Water-breathing | 16 | Seaweed, Fish bile |