The defense of necessity applies when you commit a crime in an emergency situation and you acted to prevent significant bodily harm to yourself or to another person. Significant bodily harm means death or serious injury. You also have to show that you had no alternative to committing the crime. An example of this would be that even if the defendant called the police that the harm could not have been prevented. The defense of necessity also states that the act you created does not create a greater danger than the one you were trying to prevent. You must have a reasonable belief that it was necessary to commit this crime to prevent something worse from happening. However, you cannot assert the defense of necessity if you played a substantial role in creating the emergency.