A more thorough explanation:

Definition: Retributive danger is a type of danger that an occupier of land creates to injure trespassers. It is a concealed danger that is only lawful to the extent that it could be justified if the occupier had inflicted the injury personally or directly to the trespasser. Examples of retributive danger include spring guns or land mines.

Example: If a person sets up a spring gun on their property to injure trespassers, they are creating a retributive danger. This is because the spring gun is a concealed danger that is intended to harm anyone who enters the property without permission. However, this type of danger is not lawful because it could cause serious harm or even death to the trespasser.

Explanation: The example illustrates the definition of retributive danger by showing how a person can create a concealed danger to injure trespassers. The use of a spring gun is not lawful because it is an extreme measure that could cause serious harm or death to the trespasser. Instead, the occupier of the land should use reasonable means to protect their property, such as installing a fence or posting warning signs.