That action which is undertaken out of delusion, without regard for consequences, loss, harm to others, or one's own capacity — that is called tamasic.

Tamasic action is defined by its fundamental unconsciousness: it begins from moha (delusion) and proceeds without consideration of consequences (anubandha), without awareness of destruction (kṣaya), without concern for harm to others (hiṃsā), and without honest assessment of one's own capacity (pauruṣam). This is the action of the person who acts without thinking, who plunges into situations without understanding what they are getting into, who harms others through carelessness rather than intention, and who consistently overestimates or underestimates their own resources. Tamasic action is not evil in intent — it is asleep. Its damage comes from unawareness.