There are three types of poison:
Some poisons can be harvested from natural sources (e.g. toadstools, poisonous frogs, etc.). Other poisons can be made using alchemy.
When a character is wounded by a weapon that is smeared with a blood agent, the chance of that wound becoming infected is increased by +4. Normal rules for infection then apply to the wound.
When a character is affected by a nerve poison, he/she immediately receives poison damage equivalent to a Scratch. The poison damage will then increase in seriousness over time until it reaches the maximum damage level. The maximum damage level is determined by the amount of poison that the character received (i.e. a fatal dose, a critical dose, a serious dose, etc.); a small amount of a very toxic poison will have the same effect as a large amount of mildly toxic poison.
The rate at which poison damage increases depends on the type of poison:
| Poison type | Rate at which damage increases |
| Slow-acting | One level every 5 minutes |
| Normal | One level every minute |
| Fast-acting | One level every combat turn (5 seconds) |
If poison damage reaches Fatal levels, the character dies.
Slow poisons work like nerve poisons, except that the dosage is built up slowly over a period of time rather than in one exposure to the poison. As the dosage builds up, the poisoned character's poison damage increases, until eventually they die.
There are only four ways that a poison damage can be reduced:
A character can attempt to treat a person poisoned with a nerve poison, by removing the poison from the character's body. If the poison was ingested or inhaled, this will normally involve making the person vomit; if the poison entered the character's body through a wound, it will normally involve sucking or cutting the poison out of the wound. When a character attempts to treat poison, he/she should make a dice roll using his/her Medicine (including Treating poison specialism) + IQ.
The difficulty depends on how long it has been since the nerve poison entered the character's body:
| Time since nerve poison entered body | Difficulty |
| Same combat turn (within 5 seconds) | 5 |
| Next combat turn (within 10 seconds) | 7 |
| Within a minute | 10 |
| Within 5 minutes | 13 |
| Longer than 5 minutes | 16 |
A successful dice roll will remove all remaining poison, halting the poison damage (i.e. stopping it from getting any worse, but any damage already received will stay until healed). If the dice roll fails by three points or less, some poison is removed, and the poison dose is effectively reduced by one level (e.g. what wound have been a fatal dose will now only be a critical dose), limiting the maximum level that the poison damage will advance to (again there is no effect on any poison damage already received).
More than one attempt to treat poison is allowed. Each attempt takes a whole combat turn (5 seconds) for the treater and poisoned character. The difficulty to treat is increased by +2 for each previous attempt that has been made to treat the same poison.