Chemical warfare was unlike any weapon used in World War One. Just the idea of taking chemicals that were intended for agricultural and industrial purposes and turning them into a mass-produced weapon is seemingly unconscionable. Additionally, the side effects of being exposed to any particular poison gas were either death or permanent damage to one's eyes, lungs, and skin which was also particularly cruel. Some innovations in chemical warfare technology unfortunately resulted in more destructive poison gases that were deadlier than previous ones. Even though the invention of the gas mask saved countless lives, some poison gases, such as mustard gas, were designed to penetrate the both the gas mask and the clothes that soldiers were wearing in order to inflict maximum damage.
The tank was a truly revolutionary piece of armored vehicle technology. Scientists and engineers designed a machine that was not bound to rail roads, like trains, or asphalt roads, like cars. The tank reduced the effectiveness of trench warfare because it was able to withstand enemy fire in no-man's-land and it was able to cross enemy trenches with ease. Tanks effectively replaced the need for cavalry units and foot soldiers were much more successful when tanks were able to push through enemy lines. Although the Germans were unable to capitalize on the invention of the tank, they were able to build wider trenches which would effectively trap the tank within the trench and could help stop an Allied advancement.
For hundreds of years the United Kingdom's navy was the largest and most powerful navy in the world. The Dreadnought class battleships at the beginning of the twentieth century were created as a result of the United Kingdom's industrial might and naval power. The development of submarines was another revolutionary piece of technology that relied on both stealth and torpedoes to sow fear into the hearts of thousands of sailors and civilians alike. From the German point of view the use of "unrestricted submarine warfare" was a logical response to the United Kingdom's blockade of the North Sea. The Germans were desperate for supplies and resources and assumed that any ship, military or commercial, sailing across the Atlantic Ocean was providing resources to the United Kingdom.
Aviation was an entirely new field of warfare technology. The development of the airplane was still a new piece of technology but its potential to fly over trenches and survey enemy territory was extremely valuable. In fact, reconnaissance aircraft became even more important as the war progressed. As both sides developed reconnaissance aircraft, both sides developed new weapon technology such as machine guns and anti-aircraft guns to either protect reconnaissance planes or destroy them depending on the situation. Eventually air-to-air combat and aircrafts heavily armed with machine guns and bombs, which could destroy ground troops and other enemy pilots, became a natural progression in World War One.