In wars during the XIX century, troopers could feel safe by backing a couple of meters away from musket fire. The tactic worked just fine until the first snipers appeared in the 1900s.
They were brilliant shooters who could be only be noticed when a solider died on a battlefield. They drove the enemy crazy with their spirit and unpredictability. Snipers instilled a sense of fear and coldness up against close-quarters combat, and turned well-known military tactics on their heads.
By the XXI century, designers and artificers perfected sniper rifles. Today, such weapons can fight against a tank or a helicopter, one-on-one. I am sure you can guess that size matters here.
Via: MAD LAB