Final answer:
The least favorable discharge awarded by a special court-martial is Other than honorable. This discharge is less severe than dishonorable discharge but still carries negative consequences for the individual.
Step-by-step explanation:
The least favorable discharge that can be awarded by a special court-martial is known as Other than honorable. This type of discharge is less severe than a dishonorable discharge, but it still carries negative consequences for the individual's military career and future benefits. Other types of discharges that can be awarded by a special court-martial include Bad conduct discharge and General discharge.