Jaegers are a special type of mobile mechanized robotic weapon in the Pacific Rim Universe. The Jaegers were the most effective first and last line of defense against the Kaiju during their invasion and attempt to eliminate humankind.
As an alternative to nuclear weaponry, Jaegers were designed to generate as much kinetic energy as tactical ordnance. They were built to match the estimated scale of Kaiju, and minimize damage created by conventional weapons. However, given the toxic nature of the Kaiju, Jaegers were required to rely on hand-to-hand combat and close-quarters weapons such as swords or other blade-type weapons. In conjunction with close-quarters combat, they used heat-based weapons such as the Plasmacaster.
Jaegers are handled and maintained by dedicated teams assigned to each mech and are controlled by two pilots stationed inside the Conn-Pod. Pilots are equipped in a type of specialized armor that allows them to simultaneously interface with the machine. The pilots' very minds are connected in a neural bridge that allows them to control the machine's every movement.
The development of the Jaeger program was not cheap. The cost of building the Mark-5 Jaeger Striker Eureka was reported to be over a hundred billion dollars, more than ten times the cost of a nuclear aircraft carrier.