The Zahna battlefield

The actual battlefield resulted slightly different that the depicted in the first (official) map (see below). The main difference lies on the right Prussian flank, which is not open and in the air, but is actually covered by an isolated farm located into a soaked little valley, traversed by a small stream and surrounded by labour fields, i.e. a zone of rough terrain.
Tauentzien, the Prussian C-i-C, immediately took advantage of that feature, detaching two Reserve battalions, one Landwher cavalry regiment and 1/2 battery to occupy that strong-point, allowing him to menace and fire on the left flank of the expected French attack.

The rest of the Prussian force was disposed in two all-arms lines. The first included two battalions occupying Zalsmdorff, whereas the second line awaited in close support with its cavalry deployed in the left flank.

The Oudinot attack plan is simple: a frontal assault against the Prussian center while simultaneously watching the Prussian farm with one brigade of the 13th Division. The main attack will be carried out by the 14th Division, with one brigade attacking Zalsmdorff and the other breaking through the Prussian units in the open. The 29th (Bavarian) division and the 29th Light Cavalry Division will be maintained in reserve, to deliver the final coup de grâce.

You can see all these dispositions at the main web site.