NRCAT uses the definition of torture included in Article I of the U.N Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment. The Convention came into force on June 26, 1987, following ratification by the 20th nation. June 26th is now recognized as the UN International Day in Support of Torture Victims.
The Convention was signed by the U.S. in 1988 and ratified by the U.S. Congress in 1994, thereby being incorporated into U.S. law.
Here is the definition of torture from Article I of the Convention:
“For the purposes of this Convention, the term ‘torture’ means any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining from him or a third person information or a confession, punishing him for an act he or a third person has committed or is suspected of having committed, or intimidating or coercing him or a third person, or for any reason based on discrimination of any kind, when such pain or suffering is inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity. It does not include pain or suffering arising only from, inherent in or incidental to lawful sanctions.”