He studied law himself, and at a young age joined a literary circle with his friends Franz Werfel, Paul Kornfeld and Johannes Urzidil.

This circle, which met in Prague at the Café Arco, also included Ernst Polak, the husband of Milena Jesenská.

The literary magazine Welt im Wort (World in the Word), founded by Haas in Prague, soon ceased publication for financial reasons.

After the German occupation of Prague in 1939, he went first to Italy and from there to India, where he worked as a screenwriter for at least two Indian films by Mohan Bhavnani.

[5] Haas was married three times: from 1921 to 1925 with the translator Jarmila Ambrozova, from 1925 to 1936 with Hanna Waldeck (who gave birth to their son in 1925), and from 1947 with Herta Doctor.