induration. 1. the process of hardening or being hardened.
1 They're weak against the Ice and Water types in reference of erosion, which cause this elements to the ground. 2  They're immune against the Electric type because in real life, the ground is a natural sink of electrons.  The Bug type resists them because many bugs like worms live inside the ground and many of them eat it.
Just to make this perfectly clear, every stateâs laws are subtly different from similar laws in other states. This is a general overview. Castle Doctrine applies in your home, if you are already inside. Stand Your Ground applies outdoors and only changes one element of the justification for the use of deadly force.