What is a common characteristic of narcotics?

Narcotics are primarily characterized by their ability to induce sleep or provide pain relief. This is due to their effect on the central nervous system, where they bind to opioid receptors in the brain, leading to decreased perception of pain and often resulting in sedation. This property makes them effective for managing pain, especially in clinical settings.

While some narcotics may have legal applications and be prescribed for medical use, they are not exclusively legal substances, nor are they limited to only medical use. Additionally, not all narcotics are intoxicating in the sense of causing euphoria or impairment, as their primary role in medicine is pain management and sedation. Hence, their defining characteristic remains their capacity to induce sleep or relieve pain.