Iowa allows the use of deadly force when it is believed necessary to protect one's self or others from injury or death. There is no duty to retreat when in one's home or place of business. When outside it required that the person attempts to retreat if they can without "entail[ing] a risk to life or safety." Reasonable force maybe used to stop or prevent criminal acts against personal property and possessions.
Castle Laws are laws that address the use of force when defending one's self inside their home, or on their property. Some states expand this to vehicles, and the person's place of work. Castle Laws generally include: the places where this law applies, the requirements fro use of deadly force, if there is a duty to retreat, the amount of force that maybe used in defending one's self or others. These vary widely from state to state.