Mischling Test refers to the legal test under Nazi Germany's Nuremberg Laws that was applied to determine whether a person was considered a "Jew" or a "Mischling" (mixed-blood).
On 11 April 1933 the regime promulgated the First Supplementary Decree for the Execution of the Law of Restoration of the Professional Civil Service, colloquially known as the First Racial Definition. This implementing decree stipulated that a person would be regarded as a racial Jew for purposes of the law if he had one Jewish parent or one Jewish grandparent, i.e. if the ancestor was "of the Jewish faith."
Under the law, Jews were to be discharged from the civil service, unless they had been employed since before World War I or unless they had fought on the front lines in the war, or had a father or son who had been killed in the war.
The "one Jewish grandparent" rule was predominant for a period of time in the Third Reich, and had typically been the test incorporated into the so-called Aryan Paragraph, which had been in currency before Hitler's assumption of power on 30 January 1933. However, various social and political factions militated in favor of a new set of discriminatory laws, which were forthcoming at the NSDAP party rally in 1935 in Nuremberg.
The Nuremberg Laws, as originally promulgated in September 1935, used the term "Jew" but did not define the term. The definition of the term was problematic for the Nazis and it was not until the issuance of a supplementary regulation in mid-November 1935 that a legal test that was specific to the Nuremberg laws was formally published.
The original draftsmen of the Nuremberg Laws, puzzled over the problem and pressed for a quick solution, solved it by the simple expedient of limiting the meaning of the term to encompass only "full Jews" (German: Volljuden). This test was relatively easy to state and apply, but Hitler vetoed the idea, without stipulating what he wanted as a replacement.