Troika literally means "a group of three" or "triad" in Russian.
The first "operational troikas" (оперативная тройка) were introduced in the "centre", in the Moscow military okrug in 1929. The qualifier "operational" denotes they were based on the operational departments of the state police (OGPU).
In January 1930, as part of the collectivization program, the Soviet Politburo authorized the state police to screen the peasant population of the entire Soviet Union. Normal legal procedures were suspended and the corresponding OGPU order of 2 February specified the measures needed for "the liquidation of the kulaks as a class". In each locality, a group of three people, or "troika", would decide the fate of the peasants branded as "kulaks". The troika, composed of a member of the state police, a local communist party secretary, and a state procurator, had the authority to issue rapid and severe verdicts (death or exile) without the right to appeal. In effect they served as judges, juries, and executioners.
Gradually, troikas were introduced to other parts of the Soviet Union for various and different purposes: "court troikas" (судебная тройка), "extraordinary troikas" (чрезвычайная тройка), and "special troikas" (специальная тройка).