The untitled and anonymous text known by modern scholars under the name Wu xing zhan 'Prognostics of the Five Stars [sc. 'planets']', datable to before 168 bce, is the earliest known surviving Chinese document to give a substantive account of the apparent motions of the five visible planets, and to discuss the significance of those motions. The text includes tabulated predictions of the motions of three planets (Jupiter, Saturn, Venus) from 246 bce to 177 bce. In each case it is possible to reconstruct simple rationales for the data given. It is however clear from the text that its primary purpose is to serve as an aid to celestial divination rather than as an attempt to discover laws of planetary motion for their own sake. The user of the text was not only expected to observe deviations from the rules underlying the tabulations given, but also actively to exploit such deviations as means of prognostication.