Hutier spent the first year of the war as a divisional commander in France, performing well but not distinguishing himself until the spring of 1915, when he was transferred to the Eastern Front. There, he became a corps commander attached to the German Tenth Army, and helped that force conquer large parts of Russian-held Poland and Lithuania over the next two years.
After rising to army command early in 1917, Hutier began to apply the lessons learned from his three years of commanding troops, along with his study of tactics used by other armies. He devised a new strategy for the Germans to break the stalemate of trench warfare. These tactics were to prove so successful in 1917 and 1918 that the French dubbed them "Hutier tactics", although the more commonly used term today is "infiltration tactics".
Hutier had noticed that in many previous battles, the convention method of launching an attack, with a lengthy artillery barrage all along the line followed by an assault from massed infantry, was leading to disastrous losses. He suggested an alternate approach, which consisted of these basic steps:
1: A short artillery bombardment, featuring heavy shells mixed with numerous poison gas projectiles would concentrate on neutralizing the enemy front lines, but not to destroy them.
2: Under a creeping barrage, German shock troops (sturmbatallionen) would move forward and infiltrate the Allied defenses at previously identified weak points. They would avoid combat whenever possible and attempt to destroy or capture enemy headquarters and artillery strongpoints.
3: After the shock troops had done their job, German Army units, heavily equipped with machine guns, mortars and flamethrowers, would make heavy attacks along narrow fronts against any Allied strongpoints the shock troops missed. When the artillery was in place, officers could direct the fire wherever it was needed to accelerate the breakthrough.
4: In the last stage of the assault, regular infantry would mop up any remaining Allied resistance.
Many other generals had planned attacks along similar lines in the past, dating as far back as United States Army Colonel Emory Upton at the Battle of Spotsylvania Court House in 1864. Allied generals had done so on a small scale in earlier battles in France. But Hutier was the first commander to employ them on a wide, ongoing scale.
On September 3, 1917, Hutier, in command of the German Eighth Army, broke a long siege of the city of Riga with his tactics. He followed that up with an amphibious assault (the only successful one of the war) to seize Russia's islands in the Baltic Sea.
Although Hutier wasn't present, other German forces used his ideas that fall to win a spectacular victory over the Italians at the Battle of Caporetto. Hutier was awarded the Pour le Merite by Kaiser Wilhelm II and transferred to the Western Front for 1918.
In March of that year, Hutier again employed the infiltration tactics and hammered the Allied line along the gap between the French and British armies, advancing some 40 miles along the Somme River toward Amiens. The Germans took 50,000 prisoners and Hutier won the Oak Leaves to go with his Pour le Merite.
His tactics were used in another major victory against the French in June, but the Allies had begun to develop a response to it. In July, when the Germans again moved forward in what became known as the Second Battle of the Marne, the American and French defenders had created a deep defensive system which the shock troop units (who were decimated by this time) failed to break.
Still, Hutier returned to postwar Germany as a hero. Like his overall commander and cousin, General Erich von Ludendorff, Hutier maintained that the German Army had not been defeated in the field, but was stabbed in the back by enemies on the homefront.