The southern border with Switzerland and Austria is somewhat mountainous, although very little Alpine territory actually resides within prewar German borders Lake Constance (the Bodensee) forms part of this southern border with Switzerland and Austria. Foothills dominate the Czechoslovakian border.

Much of the German interior is heavily forested, most prominent being the Black Forest region near the Alsatian border. The coastline consists mostly of flat, arable land and the East Frisian marshes, which together form part of the North European Plain. The border states of Rhineland and Moselland are demilitarised in 1936, and the German Reich cannot move forces into the area until it completes the Rhineland national focus, or if it gets involved in a war before doing the Rhineland national focus. Additionally, the exclave of East Prussia runs from the Baltic Sea to the north to Lithuania to the northeast and has Poland to the east, south, and west. Clockwise from the north, Germany borders Denmark, Poland, Czechoslovakia, Austria, Switzerland, France, Luxembourg, Belgium and the Netherlands. In 1936, the German Reich is one of the largest countries in Europe, spanning parts of both Western and Central Europe from the Rhine to Silesia, and from the North and Baltic Seas to the Alps. That being said, the player can freely change the course of events and either change the course of Germany's path or steal the spotlight as another country. Germany is in many ways 'the star of the show' in Hearts of Iron IV, with both historical precedence and technical precendence, as it acts as the primary driving force of many early-game events in historical playthroughs and is also usually the instigator of World War II, with many of the in-game events and focus trees tailored to bring about a conflict roughly comparable to the real-life counterpart. Historically, the German Reich precipitated the Second World War by attacking Poland on 1 September 1939, and would go on to establish a brief but notorious hegemony over continental Europe and the German Reich closed down the European Theatre of the Second World War through its surrender and fall between 4 May and. Germany was the primary Axis Power in the European Theatre.

By 1936 the NSDAP had cemented its power, having purged most of the opposition, and thus could focus on preparing for the next war. The troubled Weimar Republic would exist until 1933 when the NSDAP seized power and was transformed the country into a fascist dictatorship led by Adolf Hitler. After the collapse of the German Empire in the November Revolution of 1918/19 after WW1 the Weimar Republic was proclaimed, named after the German city where its constitutional convention was held. The German Reich (or often just referred to as Germany for short in community parlance) is the current incarnation of Germany.

Hearts of iron iv germany