Rubinstein was Jewish, and his family planned for him to become a rabbi. However, he did not finish his studies, and chose to devote himself to chess entirely. The decision came in 1903 after he won fifth place at a tournament in Kiev. He learned to play chess when he was 16,<ref name="H/W">Hooper D. and Whyld K. 1992. "The Oxford Companion to Chess". Oxford.</ref> and played with the strong master Gersz Salwe in Łódź.