Shiver is a potent, hallucinogenic drug made from the processed venom of the dream spider. It is generally ingested after which the user falls into a deep slumber filled with vivid dreams. While asleep the user generally shakes and shivers, which is where the drug earned its moniker. The venom of the dream spider has highly hallucinogenic properties, to which anyone who has ever been bitten can easily attest. It is not addictive, however, until it is boiled in a mixture of alcohol, water, and the spider’s webbing. The process is quite time consuming and difficult, requiring a competent alchemist. Once distilled in this way it becomes highly addictive, and a user must take shiver on a weekly basis or suffer severely adverse consequences to his mental well-being.

Shiver addiction is generally thought to be a problem of the lower classes. A single dose of shiver, generally sold in small glass vials, costs around 10 gp, although demand and the level of prohibition can drive the price up to five times that amount. In Korvosa, for instance, where the use of shiver is tightly controlled, although not technically illegal, the price for a dose generally fluctuates around 25 gp. This means that people of few means generally turn to vice in order to procure the needed funds. Desperate individuals have even been known to track down dream spiders in their lairs to let themselves be intentionally bitten, a dangerous proposition at best.