"Non-stop Domain Creation" 

People who wanted to create a domain would first create a flat field, and after it was successful, they would try to develop the domain into a domain embryo. 

In this process, domain masters might fail to upgrade their domain into a domain embryo, and it happens for various reasons, such as their own limited imagination, the not-detailed domain, not understanding the law of nature, and so on. 

Usually, people would stop right after making a flat domain, and they would spend years or even decades comprehending the law of nature so that they could upgrade their domain. 

This method would not let them fail, but once they tried to upgrade their domain and it failed, their domain would stay as a flat domain forever. 

The same goes for domain masters who wanted to upgrade their domain from a domain embryo to a complete domain. 

They might spend a longer time upgrading their domain, but domain masters generally live long.