Born Jonathan Berthold Lasker, he was an elder brother of Emanuel Lasker.
He spent most of his life in Berlin, where he played in local tournaments. In 1881 he shared 1st with Siegbert Tarrasch, and took 2nd, behind Curt von Bardeleben, there. In 1883, he tied for 1st-4th and took 4th (playoff) - Hermann von Gottschall won. In 1887, he tied for 5-6th (Max Harmonist won). His best achievement was a tie for 1st place with his brother Emanuel Lasker at Berlin 1890. He took 2nd, behind Horatio Caro, at Berlin 1891. He took 10th at Berlin 1898/99 (Theodor von Scheve, Emil Schallopp and Caro won).
In 1902 Lasker won the New York State championship.
He and his brother Emanuel wrote a drama called "Days of Mankind". It contained deep philosophical symbolism, and the theme was "redemption for rationalists and rigid logic truth through the emotional powers of mysticism.