The game simulates the largest battle of the Polish Defensive War of 1939. The battle was fought near the Bzura River, west of Warsaw, between 9 and 19 September, 1939. The first stage of the battle was a Polish counter-offensive, which was successful. However, gradually, the Germans managed to halt it, outflanking the Polish forces and counter-attacking. Eventually, as a result of the battle, Polish Poznań and Pomorze Armies that took part in the battle were destroyed. The road to Warsaw was now open to German armies marching from Silesia. This is a new edition of the "Bzura 1939" game that is based on the WB-95 wargaming system developed by Taktyka i Strategia. The previous editions of the game were based on different wargaming systems (e.g. W-39).