Machine Guns: Rapid-firing firearms capable of firing hundreds of rounds per minute. They were instrumental in trench warfare during World War I but also led to devastating casualties.
Poison Gas: Chemical substances used as weapons during World War I to cause injury or death through inhalation or skin contact. This introduced a new level of terror and suffering to the battlefield.
Tanks: Armored vehicles that could cross difficult terrains and withstand enemy fire. Tanks revolutionized warfare by providing mobile firepower and protection for soldiers.