From the Avalanche Press website:
Battles of 1866: German Armies
As war loomed over Germany in the early summer of 1866, Bavaria aligned itself with Austria against Prussia and armed for war. The Bavarian chief of staff, Ludwig Freiherr von der Tann, met with the Austrian leadership and suggested that the Bavarian army march into Bohemia. There they would form the left wing of the Austrian North Army, and hold off the Prussian First Army at Jicin while the Austrians dealt with the Prussian Second Army.
Von der Tann’s bold plan might well have given the Allies victory, but the Austrian commander, Ludwig von Benedek, turned him down and Bavaria pursued a separate strategy. By the time Benedek changed his mind and called for the Bavarians to advance, it was already too late.
Battles of 1866: German Armies is a downloadable expansion set for Battles of 1866: Frontier Battles. It adds the armies of Bavaria, Hesse-Kassel and Nassau to the game as well as the Prussian Cavalry Corps and First Army artillery reserve. There are two scenarios included: a meeting engagement between the Prussian and German armies and a Prussian assault on a prepared German defense. This module is not playable separately; it requires ownership of Battles of 1866: Frontier Battles.
German Armies is a .pdf download. The playing pieces are not die-cut and mounted, nor is the scenario book printed. Instead it comes as a series of .pdf files that will need to be assembled into the game's components.