This unit was however never employed in its intended role, instead used to defend against attacks in France. In June this improper use of the unit had already cost the unit half its manpower, and for this Major Calsow was relieved, against his protests that it was not his fault the unit was not used as intended.
The new commander of the Assault Detachment from September 8 1915 was a Captain Rohr, previously commander of the Guard Rifle Battalion. The detachment was reinforced with a machinegun platoon, and a flamethrower platoon. The old infantry guns had been shown to be too difficult to move across the battlefield, and a new model was developed based on captured Russian 7.62 cm fortress guns and issued to the Assault Detachement.
Captain Rohr at first experimented with using the body armor and shields already in the Detachment's inventory, but realized that speed was better protection than armor. The only piece of armor kept was a new model of steel helmet, that would later become the standard in all German units at the end of the First World War, and throughout the Second World War.
The new tactics developed by Captain Rohr, building much on his own previous experiences from the front, was based on the use of squadsized stormtroops ("Sturmtruppen" or "Stoßtruppen"), supported by a number of heavy support weapons and artillery that was to be coordinated at the lowest level possible, and rolling up enemy trenches using troops armed with hand grenades. These tactics were tested the first time in October 1915 in a successful assault on a French position in the Vosges Mountains.
In December 1915 the Assault Detachment started giving courses to officers and soldiers of other German units, training them in the new assault tactics. Around this time the unit also changed some of its equipment to better fit its new requirements. Lighter footwear was issued, and uniforms reinforced with leather patches on knees and elbows to protect them when crawling. Special bags designed to carry grenades replaced the old belts and ammunition pouches, and the heavy standard rifle was replaced with the lighter carbine previously used by cavalrymen. While continuing educating other units, the Detachment would also participated in many small trench raids and attacks with limited objective.
The first major offensive led by the new Assault Detachment was during the first days of the Battle of Verdun in February 1916. Stormtroops from the Assault Detachment was used in the first wave leading some units into the French trenches, attacking seconds after the barrage had lifted. This generally worked very well, even though it worked much better against the first trenchline than against the less well-known enemy rear-area.
On April 1, 1916, the Assault Detachment was redesignated "Assault Battalion Rohr". Around this time it also increased its size from two to four pioneer companies. At the same time work began on transforming several Jäger battalions into new Assault Battalions.
On March 21, 1918 Germany launched a major offensive, "Operation Michael", against Allied forces, using the new methods and tactics. Four successive German offensives followed, that of May 27 and for the first time in 4 years the stalemate of trench warfare was broken. However the German advance had stalled by July and the Allies began their Hundred Days Offensive.
The stormtroops of the late WWI already resembled those of WWII in some ways, such as being armed with lightweight weapons, stick grenades, and some already sporting Totenkopf badges.
The new assault methods involved men rushing forwards in small groups using whatever cover was available and laying down covering fire for other groups in the same unit as they moved forwards. The new tactics, which were intended to achieve tactical surprise, were to attack the weakest parts of an enemy's line, bypass his strongpoints and to abandon the futile attempt to have a grand and detailed plan of operations controlled from afar. Instead, junior leaders could exercise initiative on the spot. Any enemy strong points which had not been over-run by stormtroopers could be attacked by second echelon troops following the stormtroopers.