The 1914-1918 war was the first "industrial" war. Discoveries from the mechanical revolution, combined with major advances in physics and chemistry, made it possible to develop new weapons. The Germans first used asphyxiant gases in April 1915 in Ypres, which led to the gas being called 'Yperite'. It was held in tanks that opened when the wind blew towards the enemy. The technique was not very reliable, as the poison could be blown back to the Germans if the wind changed direction. The German army then began to store the gas in shells. From 1916, the use of poison gas became widespread on all sides. In order to protect themselves, the opposing forces developed the first gas masks.

The first tanks appeared in 1916, which were British. Huge, very slow, difficult to manoeuvre and therefore vulnerable, they were first used during the Battle of the Somme.

Aviation had just emerged as a civilian invention, but was put to good use by the military forces. In the beginning, pilots essentially conducted reconnaissance missions, but real air duels also took place. Some "aces", such as Frenchman Georges Guynemer and his Stork Squadron, or the German Manfred von Richthofen, known as the Red Baron, are still famous to this day.

Flamethrowers were used by the Germans from 1914 and spread terror in the enemy camp, although they also proved dangerous for those who operated them, due to the risk of the oil cylinder exploding. The Lebel rifles used by the French army could be fitted with a 4-edged bayonet (known as the Rosalie) for hand-to-hand combat and became one of the iconic weapons of the war. Used extensively by the German army from the Battle of the Frontiers onwards, the machine gun made it possible to fire approx. 600 shots per minute and had a longer range than a rifle.

The first operational submarines date back to the very beginning of the century. The German "Kriegsmarine" used them to sink allied ships. "U-Boots" fired torpedoes under water, as well as guns on the surface.

The "Big Bertha" manufactured in the Krupp factories was one of the best known artillery guns used in the Great War. It was a giant howitzer with 420 mm calibre projectiles that could penetrate three metres of reinforced concrete. The 1897 model 75 mm gun was accurate and easy to handle, which made it one of the French army's master weapons, although it was less efficient in the trenches. The major increase in the number of shells being manufactured led to a fall in quality, which caused many accidents, so that the general staff ordered that they should only be used as a last resort.