Detailed Instructions: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Q: A Landmark decision , or Landmark court decision , establishes new precedents that establish a significant new legal principle or concept .
A:
Landmark court decisions , in present-day common law legal systems , establish precedents that determine a significant new legal principle or concept , or otherwise substantially affect the interpretation of existing law .