Tract of chaos is a type of book in ADOM. Each time one is read successfully (which usually takes over 100 turns) it will increase piety with chaotic deity, reduce piety towards other two deities, corrupt (~10% of single corruption) and slightly reduce alignment towards C-. Changes in piety can cause divine retribution, but having high piety with character's deity typically prevents that. Piety status of 'very close' is recommended for studying scripts.