Early machine guns and automatic fire weapons included the Gatling gun, a ten-barrel gun constructed by Richard Gatling in 1862; the repeating rifle invented by Ferdinand Mannlicher in 1878; and the Maxim gun patented by Hiram Maxim in 1882. These weapons led to the machine guns that decimated armies during World War I.

This firepower immensely increased the casualty rates of armies. For example, at the beginning of World War I,  a rifle fired 15 rounds per minute and a machine gun fired 600.  Fire this heavy destroyed entire regiments in a few minutes when they ventured from their entrenchments to attack the enemies' lines.

This advance allows recruiting of Modern Infantry, Machine Gunners, and Rangers, and the upgrading of older regiments to these more modern units.