Karma
Karma [Skt.] (Tib. lé; las) literally means 'action' but it also refers to the process of cause and effect whereby positive actions result in happiness and negative, harmful actions lead to suffering.
Sogyal Rinpoche says:
"Karma, then, is not fatalistic or predetermined. Karma means our ability to create and to change. It is creative because we can determine how and why we act. We can change."
--The Tibetan Book of Living and Dying, p. 99