Infiltration tactics
In August 1915, a young French infantry officer, Captain André Laffargue, put forward additional ideas in a pamphlet titled Étude sur l’attaque dans la période actuelle de la guerre (Study of the Attack in the Current Period of the War). Laffargue based his proposals in particular on his experiences in the initially successful but ultimately disappointing results of employing the tactics of Note 5779 at the Second Battle of Artois; he commanded a company of the 153rd Infantry Regiment, attacking immediately south of Neuville-Saint-Vaast on 9 May 1915. Laffargue was left wounded on the German front line but his regiment advanced another 1.5 kilometres (0.93 mi), only to be held up by two German machine guns. Laffargue's pamphlet focused primarily on the small-unit perspective, calling for mobile firepower to deal with local resistance such as machine guns, advocating that the first waves of an attack advance through the intervals or gaps between centres of resistance, which should be temporarily neutralised on the edges by fire or heavy smoke. The points of resistance would then be encircled and dealt with by successive waves. This promotes coordinating local forces to deal with local resistance as it is encountered, an important second step in infiltration tactics. Laffargue suggests that had these methods been followed the attack could have resulted in a complete breakthrough of the German defences and the capture of Vimy Ridge.
The French Army published Laffargue's pamphlet in 1915 and the following year a commercial edition found wide circulation, but as informational rather than being officially adopted by the French military. The British translated and published Laffargue's pamphlet in December 1915 and, like others, continued to make frequent use of wave attacks. The US Infantry Journal published a translation in 1916.
In contrast to the infiltration tactics then under development in the German army, the tactics of Note 5779 and as expanded by Laffargue remained firmly wedded to the use of the attack by waves, despite the high casualties which could ensue. Laffargue maintained that the psychological support of the attack in line was necessary to enable men to advance against heavy fire.
In 1916, captured copies of Laffargue's pamphlet were translated and distributed by the German army. How much this may have influenced German infiltration tactics is not known; such influence has been dismissed by Gudmundsson. The Germans had started developing their own infiltration tactics in the spring of 1915, months before Laffargue's pamphlet was even published.

Russia: The vast Eastern Front of World War I, much less confined than the Western Front, was much less affected by trench warfare, but trench lines still tended to take hold whenever the front became static. Still, about a third of all Russian divisions remained cavalry, including Cossack divisions.
General Aleksei Brusilov, commanding the Russian Southwestern Front, promoted large-scale simultaneous attacks along a wide front in order to limit defenders' ability to respond to any one point, thus allowing the collapse of the entire defending line and returning to maneuver warfare. For the Brusilov Offensive of 1916, he meticulously prepared a massive surprise attack on a very wide 400 km (250 mi) front stretching from the Pripet Marshes to the Carpathian Mountains, with the objective of Lemburg, Galicia (now Lviv, Ukraine), 100 km (60 mi) behind the well-fortified Austro-Hungarian line. The Austro-German military command was confident that these deep and extensive entrenchments, equal to those of the Germans on Western Front, could not be broken without significant Russian reinforcements.: 33–36 
After a thorough reconnaissance, Brusilov directed preparations for several months. Forward trenches were dug as bridgeheads for the attack, which approached the Austro-Hungarian trench lines as closely as 70 m (230 ft). Select forces were trained and tasked with breaking through the defending lines, creating gaps to be widened by 8 total successive waves of infantry, allowing deep penetration. Brusilov committed all his reserves into the initial assault.: 51 
Although Brusilov favoured shorter bombardments, the bombardment preparation for this offensive was more than two days long, from 3am on June 4 (May 22 old style) to 9am on June 6 (May 24). This bombardment disrupted the first defense zone and partially neutralized the defending artillery. The first infantry attacks made breakthroughs at 13 points, which were soon increased in width and depth. Austro-Hungarian response to the unexpected offensive was slow and limited, believing that their existing forces and defenses would prove sufficient; instead, reserve units sent forward to counterattack often found their routes already overrun by the Russians.: 40  The Russian 8th Army, commanded by Brusilov himself just a few months before his promotion to command the Southwestern Front, achieved the greatest success, advancing 48 km (30 mi) in less than a week. The 7th and 9th Army achieved lesser gains, though the remaining 11th Army in the center made no initial breakthroughs. The performance of individual Austro-Hungarian units during the campaign, each raised from separate diverse societies within the Empire, was highly variable, with some units long standing firm despite the odds, like the Polish Legions at the Battle of Kostiuchnówka, whereas others readily retreated in panic or surrendered, as at the Battle of Lutsk.: 78–79 : 42–44 
Though the campaign was devastating to the Austro-Hungarian Army, Russian losses were very high. German forces were sent to reinforce, and the initial Russian advantages waned. Though Russian attacks continued for months, their cost in Russian men and materiel increased while gains diminished. In the end, much like the bold French tactics of la percée at the Second Battle of Artois, these tactics were too costly to maintain. The Imperial Russian Army never fully recovered, and the monumental losses of so many Russian soldiers helped fuel the Russian Revolution of 1917, leading to disbanding the Imperial Russian Army.: 53 
Though the Brusilov Campaign impressed the German Army High Command, how this may have influenced their further development of infiltration tactics is not known. Elements of Brusilov's tactics were eventually used by the Red Army in developing their Deep Battle doctrine for World War II.

Britain: The British Army pursued a doctrine of integrating new technologies and updating old ones to find advantages in trench warfare.
At the Battle of Neuve Chapelle, March 1915, a well-planned British attack on German trenches, coordinated with short but effective artillery bombardment, achieved a local breakthrough. Though ammunition shortages and command and control issues prevented exploiting the gains, this demonstrated the importance of a combined infantry-artillery doctrine.
Initial experiences in trench warfare, shared between British and French, led both to increase pre-bombardment (requiring dramatically increased artillery munitions production), and also to supply infantry with more firepower, such as light mortars, light machine guns, and rifle grenades. While the British hoped that this new combination of arms, once improved and properly executed, could achieve decisive breakthroughs, the French moved from their pre-war grand la percée doctrine to more limited and practical tactical objectives. At this same time, the Germans were learning the value of deep trenches, defense in depth, defensive artillery, and quick counter-attacks.
This came to a head with the British Somme Offensive on 1 July 1916. Douglas Haig, commanding the British Expeditionary Force (BEF), planned on an ambitious large-scale quick breakthrough, with an extensive artillery bombardment targeting the German front-line defenses, followed by a creeping barrage leading a mass infantry assault.: 106–10 : 117–21  Despite planning, execution was flawed, perhaps resulting from the rapid expansion of the British Army. The British losses on the first days were horrific. British operations improved over the next several months of the campaign, however.: 113–6 : 183–282  Learning the limits of battle planning and bombardment, they abandoned single grand objectives, and adopted a "bite and hold" doctrine (equivalent to the French grignotage) of limited, local objectives to what could be supported by available artillery in close cooperation.: 345–84  Combining this with new arms was still promoted; Britain's new secret weapon, the tank, made its first appearance midway through the Somme operations. Though not yet effective, their promise of breakthroughs in the future was held out.
The British Third Army employed tactics giving platoons more independence at the Battle of Arras in April 1917 (most notably the capture of Vimy Ridge by the Canadian Corps), following the reorganisation of British infantry platoons according to the new Manual SS 143. This still advocated wave attacks, taking strongpoints and consolidating before advancing, part of "bite-and-hold" tactics, but this did allow for more local flexibility, and set groundwork for low-level unit initiative, an important aspect of infiltration tactics.

Hurricane bombardment: A new method of artillery use evolved during World War I, colloquially called hurricane bombardment. This is a very quick but intense artillery bombardment, in contrast to the prevailing artillery tactic of long bombardments.