[1][2] Luik first studied at Koikküla, Karula and Rõuge Parish schools and graduated from Hugo Treffner Gymnasium in Tartu.
[1] After leaving the city government in 1940, Luik worked in Tartu as a mathematics teacher.
In March 1945, following the Soviet occupation and annexation of Estonia, Luik was arrested by the NKVD and deported Tyumen Oblast, Russian Soviet Federative Socialist Republic, where he died in 1948 in Tobolsk of tuberculosis while serving a five-year sentence.
[3] Karl Luik was married to Helene Kaas and the couple had three children; two daughters and a son.
In 2016, the Tartu City Government decided to erect a monument to Luik in Vanemuine Park.