In order for you to be able to use force to defend yourself under Arizona law, the threat against you must have both of two conditions:

1) The threat against you must be immediate.

You CANNOT use force against a future threat. If someone says to you, "I'm going to go home, get my Lightweight Officer's Model, with Meprolight Tritium nite sights, load it with a Glaser Safety Slug, followed by a Mag Safe, and 5 185 grain +p Hornady hollow points, then come back and shoot you in the second shirt button", you CANNOT use force on this person. It's a future threat.

2) The threat against you must be an UNLAWFUL act.

The act that someone commits must be a crime for you to be able to use force against them. A burglar has no "right" to self defense during the burglary. The standard of the use of this force in self defense is what a reasonable person would believe is immediately necessary under the circumstances.

The use of physical force is NEVER justified by verbal provocation alone, or to resist an arrest that the person knows or should know is being made by a peace officer or someone acting at the direction of a peace officer, unless that force used to make the arrest exceeds the amount of force allowed by law.

In order to maintain the viability of self defense in any prosecution, the user of the force must clearly communicate to the other combatant that they have no desire to engage in a fight, and to stop using force if the assailant withdraws or clearly communicates their desire to withdraw.

Example: You're on a Saturday husband drag through the local busy mall. While distracted by the widow display at Fredrick's, a local baggy pants homeboy bumps into you, then becomes irate. As he approaches you in a hostile manner, YOU must deescalate the conflict. Even though he bumped into you, it is wise to apologize and carefully withdraw from the conflict. If you engage in any fighting words, or you assume a "fighting stance", the witnesses will report "an altercation". This will not go well for you when the police arrive. If on the other hand, you carefully back away from the assailant with your hands in front of you, palms out so that you can shove him away if necessary, you preserve your physical posture and your legal defense as well. The witnesses will now report an "attacker" and a "defender".

Tell him that you are sorry, and that you want no part of him, and to leave you alone. If he persists, order him away in a increasingly louder tone. If he gets within striking distance, tell him you'll use force to defend yourself. If you have a defensive tool such as pepper mace or an ASP baton, now is a good time to get it ready. Remember that unless he has a weapon, deadly force is neither called for nor justified.

If you are a guy, don't use profanity. It sounds angry. If you are a woman, get as blue as you can. It shocks a bad guy because it is less expected from women and it tends to throw a bad guy off guard.

One more thing - if you carry any weapon and you allow an altercation to escalate without trying to deescalate, the fact that you brought the weapon is evidence against you as to the premeditation to use force. Remember that courts have little to do with the truth. They have to do with what you can make people believe.