Trench warfare
Trench warfare prevailed on the Western Front from late 1914 until the Germans launched their Spring Offensive on 21 March 1918. After the buildup of forces in 1915, the Western Front became a stalemated struggle between equals, to be decided by attrition. Frontal assaults, and their associated casualties, became inevitable because the continuous trench lines had no open flanks. Casualties of the defenders matched those of the attackers, as vast reserves were expended in costly counter-attacks or exposed to the attacker's massed artillery. There were periods in which rigid trench warfare broke down, such as during the Battle of the Somme, but the lines never moved very far. The war would be won by the side that was able to commit the last reserves to the Western Front.
German military rifles
The needle gun first made its appearance in street fighting during the May Uprising in Dresden in 1849. It also played an important role in the Danish–German War of 1864. The gun saw its heaviest use in the Austro-Prussian War of 1866 and the Franco-Prussian War of 1870-71. Because the breech-loader made it possible for a Prussian soldier to fire five (or more) shots, even while lying on the ground, in the time that it took his Austrian counterpart to fire one (and then reload while standing), it was seen as allowing the Prussians to sweep the field.