Both types needed to be cheap to build, given the difficult financial position of many Germans after World War I and also simple enough that skilled amateur builders, both within and without gliding clubs, could successfully construct them from plans.

The primary/secondary glider concept took shape shortly after the absorption of the Martens gliding school on the Wasserkuppe into Rhön-Rossitten Gesellschaft (RRG) at the end of 1925.

Martens chief instructor Fritz Stamer and Alexander Lippisch were brought together to produce two such gliders and within a few days the Zögling (English: Pupil) and the Prufling designs were complete.

with a triangular fin carrying an upright, straight edged balanced rudder which was slightly angled below the heel and extended down to the keel.

The Prüfling landed on a rubber sprung skid below the whole forward, ply skinned fuselage, assisted by a very small tailskid.

Lippisch returned to the design of secondary gliders four years later, after exploring tailless types, resulting in the RRG Falke.