गुण

In everyday Hindi "guṇa" often means merit or a good quality. In the Gita guṇa (गुण) means one of the three strands of nature: sattva, rajas and tamas. The fourteenth chapter says that these three, born of nature, bind the embodied one (14.5).

The third chapter says that all actions are performed on every side by the guṇas of nature, but one deluded by ego thinks "I am the doer" (3.27). In chapter 18 actions are said to be distributed according to the guṇas born of one's nature (18.41); this is the ground behind svadharma.

Common misreading: sorting people into "only sattvic" or "only tamasic". All three guṇas are present in every person, in different proportions; these are tendencies, not labels.

For more, see the topic One's Own Duty.