Trench Warfare
The way the trench is built was very important in WW1. The trenches were usually dug in a zigzag pattern. Otherwise, if the enemy managed to get into the trench, they could shoot straight along the line. If the trenches were dug in a straight line, any enemy that gained access at any point of the trench would have the whole trench under their control. However, if the trench was zigzag, even if the enemy managed to get in the trench, they could only control part of it. There would still be soldiers on defense (they have walls to hide behind). In addition, the reason to why they used trenches in the first place is because this new form of war known as total war was new to Europe. From this action soldiers were scared so they needed a "wall" to hide behind so they dug down.
Mustard Gas
The Germans used mustard gas for the first time during war in 1917. They outfitted artillery shells and grenades with mustard gas that they fired in the vicinity of the troop target. After encountering several attacks, the Allies referred to mustard gas as Hot Stuff or H.S., eventually dropping the S and just referring to it as H. By the end of the war, more than two dozen chemical agents had injured 1 million soldiers and civilians, killed 100,000 people and earned the well-deserved title of weapons of mass destruction.
Zeppelin
A Zeppelin is a type of rigid airship named after the German Count Ferdinand von Zeppelin who led German Zeppelin squadrons during World War I. Zeppelin's ideas were first formulated in 1874 and developed in detail in 1893. After the outstanding success of the Zeppelin design, the word zeppelin came to be commonly used to refer to all rigid airships. Zeppelins were first flown commercially in 1910 by Deutsche Luftschiffahrts-AG (DELAG), the world's first airline in revenue service. By mid-1914, DELAG had carried over 10,000 fare-paying passengers on over 1,500 flights. During World War I the German military made extensive use of Zeppelins as bombers and scouts, killing over 500 people in bombing raids in Britain.
Vicker's Machine Gun
The Vickers machine gun or Vickers gun is a name primarily used to refer to the water-cooled .303 British (7.7 mm) machine gun produced by Vickers Limited, originally for the British Army. The machine gun typically required a six to eight-man team to operate: one fired, one fed the ammunition, the rest helped to carry the weapon, its ammunition and spare parts. It was in service from before the First World War until the 1960's, with air-cooled versions of it on many Allied World War I fighter aircraft. This gun was one of the deadliest weapons during WWI. In fact it did so well that the British army used this gun until the 1960's.