##  [Law of Requisite Variety](/law-requisite-variety) 

  ##  [Law of Requisite Variety](https://engineering.quantumdictionary.io/law-requisite-variety-0) 

  

 [![Engineering & Applied Technologies Dictionary](/sites/default/files/styles/large/public/2026-01/Engineering%20%26%20Applied%20Technologies.png.webp?itok=_IKO7_-n)](/topic-specific-dictionaries/engineering-applied-technologies)



**Engineering & Applied Technologies Dictionary**

 







 

 

 

 



 

 

 

 

Definition

A cybernetics principle stating that effective regulation of a system requires a controller whose repertoire of possible responses (variety) is at least as large as the variety of disturbances or states the system may present; without sufficient controller variety, some disturbances cannot be absorbed or countered.