There are various sorts of poisons available in AD&D, including the insinuative and ingested poisons obtainable by assassins, potions of poison which must be ingested, and monster poisons (which work both insinuated and ingested).¹⁾

This section is a rules extension which provides rules for the acquisition of poison.^Ex2)

Assassins can freely purchase poisons from their guild or guild connections at the prices listed on DMG 20. Availability is based on settlement size, as below.

Non-assassins asking around about poison need to score 96 or higher on a reaction roll, success presently giving them the same purchasing options as an assassin. A failure of 50 points or more means the assassins guild caught wind of the character’s inquiries and will seek to kill them.