The name means refers to the building of cards onto an Unter (the equivalent of the Jack in a French pack).
[1] Unteransetzen is also a component of compendium games such as Rosbiratschka[3] Kein Stich or Herzeln.
Cards rank in their natural order – Sow, King, Ober, Unter, Ten, Nine, Eight, Seven – and there are no trumps.
In clockwise order, players then attempt to 'build' onto the first card by laying next to it the next higher or lower card in suit sequence i.e. the second player would play either the Ober of Hearts or the Ten of Hearts.
It is described as a simple card game in which a Jack is placed on the table and players complete the rest of the suit before and after it.