An overt act is a deliberate and open act that is designed to carry out a criminal offense.
The concept of an overt act is often used in the laws of treason and self-defense to determine whether or not a treason conviction can be made, or whether or not a person had a right to use self-defense.
When a person uses self-defense, it can sometimes result in serious harm or even the death of the attacker. This is especially true when guns are used for self-defense.
Self-defense can only be justified when an overt act of a person that demonstrates an intent to kill or harm is present. Similarly, a treason conviction can only be made if it is abundantly clear that the defendant made an overt act that was designed to commit treason.