Some states refer to it as the 'make my day law' because of Clint Eastwood's character, Dirty Harry, other states call it 'stand your ground' or the 'castle law.'
Whatever you call it, it's a controversial law that's showing its teeth right now, most recently in the Kentucky Court of Appeals.
A three-judge panel couldn't agree on a ruling regarding 'stand your ground' in Kentucky.
The court ruled 2-1, that a man acted in self-defense when he stabbed another man outside a night club in northern Kentucky back in 2008.
The one against it, Judge Kelly Thompson from Bowling Green.
"I dissented, which is like asking the Supreme Court to take the case and tell us for sure. We really had an argument over the standard and burden the Commonwealth has to overcome that new statute 'stand your ground'," said Kentucky Court of Appeals Judge Kelly Thompson.
There's a law in Kentucky called the 'castle law' and Judge Thompson thinks this instance is a bit of a stretch.
"It's gone out into bar parking lot brawls, and I don't think the law was really intended to go this far," said Thompson.
How much do people really know about self-defense laws in Kentucky?
"Unless you have been through training such as that or you have had some special interest in studying the law, you may not know of the specific coverage of the castle law, and what it's intended to protect," said attorney Phil Kimbel.
Kimbel teaches a concealed carry class telling people about self-defense.
He said it boils down to a basic point.
"The castle law says if you're confronted with serious bodily injury or death in your home, or in general circumstances of life, that you can defend yourself though against that threat," said Kimbel.
However, the threat isn't always crystal clear as shown in the case where Judge Thompson dissented.
Judge Thompson says this case will likely go before the Kentucky Supreme Court for a ruling as part of a case they choose to take.