For most of human history, it was impossible to distinguish between disease, poisoning, and supernatural threats. All of them were considered to be mysterious dangers which might affect anyone without an obvious cause. Naturally, this led to a great deal of paranoia (see Poisoning Phobias, GURPS Horror, p. 59).
The ancient Mesopotamians and Hebrews blamed illnesses on witches who put unclean material into food or water. From them, the belief seems to have spread to the Greeks and Romans, and hence throughout Europe by the medieval period.
Veneficium
9 Points
Prerequisites: None.
Veneficium is a secret folk style which uses standard prerequisites. Most practitioners are simply malicious, using it to terrorize anyone who offends them, although some use it for more practical means, such as assassination or extortion. Either way, stylists often have to worry about being poisoned by each other, so they learn some methods to defend against such threats. As well as detecting poisons, they can use the mystical process of Mithridatism to build up universal resistance to them by repeated exposure, eventually becoming entirely immune to all toxins (as Mithridates VI of Pontus was said to be).
Once the basics of the style are mastered, there are several ways to develop more dangerous methods. The most common is to learn spells which make mundane poisoning easier. Seek Poison, Extract Poison, Slow Poison, and Increase Potency are all useful for this. Gathering ingredients is aided by Seek Plant (or Fungus) and Identify Plant (or Fungus), while growing them is assisted by Heal Plant (or Fungus) and Plant (or Fungus) Growth. Locating food to poison is obviously helped by Seek Food, while No-Smell and Obscure Poison make it harder to detect. A subtle casting of Hunger can encourage a target to be less cautious about eating suspicious food.
Those who want deadly poisoning of food and drink without having to acquire or carry poison need Death’s Banquet. This requires Magery 3 and learning Ignite Fire, Create Fire, Cook, Seek Food, Create Food, and Essential Food. Those spells are almost never studied by those who aren’t trying to learn Death’s Banquet eventually.
Malefice and Ensorcelment are highly desirable for venefici, since they allow long-term torture of a victim without having to stay close to them. Learning them requires IQ 12, Magery 2, and knowing at least one spell from ten different colleges; the style’s required spells give Food, Poison, and Water. Detect Poison adds Healing and Protection and Warning. Any three of Foolishness (Mind Control), Ignite Fire (Fire), Purify Air (Air), and either Debility or Itch (Body Control) bring the total to eight. Seek Plant (Plant) and Seeker (Knowledge) then finish the set of ten, allowing the mage to learn Enchant, followed by Malefice.
Although it isn’t a martial style, veneficium has many spells which are useful in a fight. Stench is an area-effect attack which only needs Purify Air to learn and leads to the faster-acting Poison Cloud for those with Magery 2. Spore Cloud offers a less-lethal alternative for anyone who has already learned Fungus Growth. Sting is the only missile spell taught by the style, but is made somewhat flexible by spell variation, allowing it to benefit from enhancements like Accurate, Armor Divisor, Guided, or Homing.
Deathtouch is a potent melee spell with a long chain of prerequisites, which requires Magery 1. The typical route to learning it starts with Itch, Spasm, Clumsiness, Debility, and Hunger, but the last two can be substituted with Perfume and Nauseate (if Purify Air, No-Smell, and Odor are known) or Drunkenness and Sickness (requiring Foolishness). From there Paralyze and Wither Limb lead to Deathtouch. Choke and Total Paralysis are often added to this. Poison Touch is a weaker but simpler alternative for those with Magery 2, requiring only one poison spell beyond the five required by the style (Detect or Seek Poison being the usual choice).
Required Skills: Herb Lore; Poisons.
Required Spells: Decay; Foul Water; Poison Food; Purify Food; Purify Water; Seek Water; Test Food.
Perks: Convenience Casting (Fungus Growth or Plant Growth); Elixir Resistance (Death); Gut of the Dragon; Improvised Magic (Veneficium); Secret Mage; Special Exercises (Immunity to Poison); Spell Enhancement (Low Signature); Spell Resistance (Poison Food); Spell Variation (Sting); Stabilizing Skill (Herb Lore for Plant or Poisons for Poison).
Optional Traits
Attributes and Secondary Characteristics: Increased HT.
Advantages: Resistant to Poison.
Disadvantages: Callous; Paranoia; Sadism; Secret (Witch).
Skills: Alchemy; Animal Handling (Amphibians or Snakes); Cooking; Gardening; Hazardous Materials (Magical); Holdout; Innate Attack (Projectile); Intimidation; Naturalist; Sleight of Hand.
Spell List
Alter Poison*; Analyze Poison*; Apply Poison*; Blight; Choke; Clumsiness; Cook; Create Fire; Create Food; Curse; Death’s Banquet†; Deathtouch; Debility; Decay; Detect Poison; Drunkenness; Enchant; Ensorcel; Essential Food; Extract Poison*; Foolishness; Foul Water; Fungus Growth‡; Heal Fungus‡; Heal Plant; Hunger; Identify Fungus‡; Identify Plant; Ignite Fire; Increase Potency*; Itch; Madness; Malefice; Nauseate; No-Smell; Obscure Poison*; Odor; Paralyze Limb; Perfume; Plant Growth; Poison Cloud; Poison Food; Poison Touch*; Poisoning*; Purify Air; Purify Food; Purify Water; Retch; Seek Food; Seek Fungus‡; Seek Plant; Seek Poison*; Seek Water; Seeker; Sickness; Slow Poison; Spasm; Spore Cloud‡; Stench; Sting*; Test Food; Total Paralysis; Weaken Blood; Wither Limb.
* from the Toxic Grimoire (Pyramid, Volume 4, Issue 1).
† from GURPS Magic: Death Spells.
‡ from GURPS Magic: Plant Spells.
Here's a chart showing the prerequisites for the style's spells. Spells with a thick outline are required. Those with rounded corners have no spell prerequisites and so act as starting points for prerequisite chains.