NKVD troika or Special troika (Russian: особая тройка, romanized: osobaya troyka), in Soviet history, were special quasi-judicial proceedings composed of three officials from the security police (for much of the troikas' existence, the NKVD, hence the name) who issued sentences to people after simplified, speedy investigations and without a public trial. The three members acted as ad hoc judges. These commissions were employed as instruments of extrajudicial punishment introduced to supplement the Soviet legal system with a means for quick and secret execution or imprisonment. It began as an institution of the Cheka, then later became prominent again in the NKVD, when it was used during the Great Purge to execute many hundreds of thousands of Soviet citizens. Defendants in the Troika's proceeding were typically not entitled to legal aid or the presumption of innocence. Troika members employed common sense and socialist revolutionary principles to reach a verdict. Convictions usually did not include information about the actual incriminating evidence and basically contained only information about indictment and sentencing. The outcome of such trials was often predetermined before it even began due to targeted numbers of citizens to be executed or imprisoned in Gulag prison camps.
Troika means "a group of three" or "triad" in Russian.
