Jaegers are too massive and complex for a single human mind to control. The neural load would cause severe brain damage or death. Therefore, a two-pilot system (Drift) was developed to split the neural load between the right and left hemispheres of the 'brain' of the Jaeger.

Drifting is the process where two pilots align their memories and consciousness via a neural bridge. The stronger the emotional bond and synchronization between the pilots, the better the Jaeger performs. Drifting with someone essentially means sharing your deepest memories and secrets.

Kaiju are categorized by 'Categories' (I to V) based on their size, toxicity, and displacement. Category I are the smallest, while Category V (like Slattern) are the largest and most dangerous ever recorded during the war.

The Precursors, an ancient race of alien colonizers from the Anteverse. They clone and grow Kaiju using their own genetic code, designing them specifically to destroy the indigenous life of a planet (humanity) to prepare it for colonization.

A Ghost Drift occurs when a pilot is mentally connected to the memory of a co-pilot who is no longer present or has died, often resulting in chasing memories (like Raleigh Becket experienced) rather than focusing on the present reality.