As you can probably guess it is a good idea to be able to defend yourself astrally/psychically.  Almost everyone makes use of auric defenses whether they realize it or not.  You can probably remember the last time you were having a bad day and just felt like you didn't want anyone to bother you, and so you put out the 'don't mess with me' vibes.  You probably felt like you had  invisible spikes shooting out from all around your body keeping people away, or maybe you felt flames or swords all around you.  If you've felt that way before, then you've already practiced a very basic and intuitive form of psychic self-defense.

The most basic form of defense that almost every book on the topic will talk about is to create a hard protective shell or force field around your aura to prevent unwanted energies and influences from getting in.  To do this, STRONGLY VISUALIZE a hard protective force field around yourself (and around your aura specifically).  You may close your eyes and try to imagine this as vividly as possible if you need to.  Try to 'FEEL' that it is there.  See it in your imagination as clearly as possible and believe that it is being created around you.  If you need additional help to visualize a force field around youself, you can imagine that your force field looks like it's made of some impenetrable material like brick, granite, pure energy (like on a science fiction movie), or anything else that you prefer.  Don't doubt that you are being effective.  Doubts will only stop you from being effective so don't have them; make yourself BELIEVE that this force field is there, strong, and impenetrable.  You can even try powering up with energy (see section on Elemental Energy) and using it to reinforce your force field, or anything else that you build in or around your aura.  The more times you imagine that this force field exists, the stronger you will make it and the easier it will be for you to recall it every time you need it in the future.  You may safely use this technique temporarily whenever you feel threatened, or unsafe mentally/emotionally in a group of people, or if you know for a fact that you are being attacked psychically.  Energy must flow in and out of your aura, by the way, so it isn't good to try to remain completely sealed off on a permanent basis.  If you're in that much danger then there are other additional techniques to make use of for personal protection.

"What the mind dwells upon will be built" - Cayce

Your thoughts have an energetic reality on higher frequencies of manifestation 'above' the physical realm.  They are real, and if you believe something to be true about yourself (and especially about your aura), then it will tend to manifest in the way that you believe it according to your personal skills/talents, and taking into consideration the Wills of others involved in that particular instance.  Obviously believing that you are rich when you are not isn't going to cause you to suddenly be a multi-millionare...although it could help you develop the mind-set to create yourself into one through your actions in the physical realm as a result of a change in your personal views of yourself and how you conduct yourself in the world.

In the case of psychic defenses like force fields, you are acting on those higher frequencies of reality more directly (indirectly in the case of building something through visualization alone - directly in the case of clairvoyantly viewing/sensing abstract energy structures and then consciously modifying them in real time through force of will).  What you think and how you think it will determine what is created and how effective it is.  That is why you should not have doubts while creating anything, since that would only cause you to hinder your own success.  Skill is a factor too, of course.   The more times you practice doing something the better you'll be at it.  It is still possible that someone with a stronger force of Will and more skill than you will be able to break through your defenses, so don't let yourself get a big head right away just because you think you know something that no one else knows.   The biggest key to not getting into a fight is not conducting yourself in a manner that will attract one to you.

Energies of a particular quality will tend to attract other energies of a similar quality.  This appears to be true both astrally and physically.  In the physical realm, friends tend to be groups of people with similar interests, viewpoints, attitudes, and personal 'atmospheres' or 'vibes'.  Astrally, positive entities will tend to attract other positively charged/dispositioned entities.  If you surround yourself with negativity, then it is very likely that you will attract even more of the same to yourself.  This will include negative entities who wish to leech energy off you, and people/things that want to fight with you physically and astrally.  I personally feel it best to maintain a positive, warm, and loving atmosphere energetically within and around you as often as possible.  This ensures that those looking for a fight will be less tempted to bother you since those energies and feelings are incompatible with fighting, and the people and 'things' you attract will tend to be more in harmony with the vibes that you're giving off.  I have seen cases where some entities and people actually feed off such positive energies in a negative way, but these appear to be rarer and less obvious than those that feed off the negative energies/vibes.  The benefits of maintaining a positive personal environment both internally and externally far outweigh the consequences of perpetual negativity.

There are instances where being positive and creating a personal force field are not enough to dissuade someone from trying to harm you.  When that happens you need to take an active role in your personal safety, and by this I mean combat.  Normal humans do many defensive and offensive things with their energy on a regular basis without realizing it, i.e. lashing out with their energy to strike another person while in a heated debate (usually the energy 'strike' will be accompanied with dagger like words), or grasping another person with their energy in the effort to hold their attention while talking to them (usually done by someone who believes himself to be correct no matter what and who wishes to MAKE the other person see things his/her way and forcibly agree).  These are just 2 simple examples of ways in which common people intuitively use their personal energy fields in an offensive or defensive manner.  If it should become necessary, it is possible to apply your Will and your energy in a more conscious way to engage in actual combat either while astral, or just psychically while in the physical body (but still viewing astral events etc.).  To do this, first review the section on Elemental Energy.  When you understand the basic concepts of energy usage, then here are some ideas you can use to protect yourself and others:

Astral Weapons:  Power up with energy of an appropriate type, and then use it to create a weapon by visualizing an astral/mental weapon of your choice.  Use an energy type according to its qualities and attributions for best results.  With the weapon clearly visualized and feeling 'solid' and real to you astrally, you may use it to strike at an opponent IN SELF-DEFENSE (remember the 'like attracts like' observation?).  Fireballs, missiles, guns, etc. are all very common examples.  You won't see the weapon physically, of course.

Wiping off Wounds:  If you feel that something/someone has struck you with their energy with the intent to harm you, then imagine yourself wiping off the negative energies of their strike from wherever you feel that they hit you.  Doing so will remove the residual energies from their attack that might still cause some damage if your defenses happen to relax later allowing those energies to finally get into your personal energy field.

Force Fields/Shields:  See above.

Defense Systems:  If you understand how to work with energy and create astral structures then it's a simple matter to create a defense system for a room or a house.  You may have to recharge it on occasion to keep it strong.  BE CREATIVE.

A helpful Tip- Obvious and easily seen defensive structures tend to act like an astral neon sign that reads "Please come over here and kick my ass because I'm putting out the defensive/war-like vibes while hoping that someone won't come over looking for a fight."  It might be a good idea to tone it down a bit to avoid showing up like a xmas tree on the radar screen of every demonic bad ass that flies over your house looking for trouble  ;)    Just a simple defense system that encourages a positive atmosphere while keeping out negativity will suffice for most people.  Like all astral structures, the only things limiting you are your own personal skills and creativity.

Because I am aware of the possibility for misuse of the information found on this page (and on this site in general) I thought a brief word ought to be made on what has been referred to as Karmic Action by several ancient and modern sources.  I have observed through my own work that there appears to be a cause-and-effect relationship to one's actions in the universe, with a constant balancing action taking place as a result.  Everyone appears to 'get what they give' regardless of who they are.  Just as I have mentioned previously, if you conduct yourself in an offensive/negative manner, you will inevitably ATTRACT the same types of energies and events to yourself that you are sending out on a regular basis.  Similarly, if you actively manipulate and cause harm to others (i.e. act against their will for your personal gain) then you will receive the negative effects of your actions upon yourself.  This isn't the result of some all-powerful 'god' punishing you for wrong doings (though there are entities that take it upon themselves to police certain individuals if enough complaints are made about them), this is simply the unemotional and unbiased action of the universe in an attempt to rebalance itself.  Morality is a human invention and doesn't even enter into the picture unless you believe that you are going to be punished for some perceived wrong-doing.  As long as all parties involved are consenting to whatever you are doing then you normally have nothing to be worried about concerning any appreciable karmic/energetic backlash as a result of your actions.

I sometimes use a tub/pool analogy to describe karmic action:  If you put your finger in standing water in a tub or pool and create ripples, eventually the water will hit the sides of the pool and bounce back.  Even if you have stopped creating these ripples the water must continue to bounce back and hit the origin of the waves (your finger) until the energetic response that resulted from the motion is exhausted.  Exactly WHEN the response will exhaust itself in its return to you will vary according to other known and unknown factors.  Don't worry, you can't escape karmic action; balance must always prevail.  What some people notice after making a drastic change in the way they conduct themselves in relation to other people is that although they've changed inside, they still continue to receive a backlash from before.  This is normal and usually occurs until the energetic response from their previous actions exhausts itself.  Creating a positive response through frequent altruistic, generous, and loving behavior will probably benefit you more so than not (just a suggestion).  Overall I prefer to create positive ripples in my 'pool.'

Your 'karma' is constantly being created all the time.  Your present actions and intentions are currently shaping your future, and the present realities you experience now are the result of your past actions and intentions.  In this manner, you are more in control of your personal realities than most people ever realize.  Such thinking eliminates the worry of guilt or 'sin' since YOU punish you, not some all powerful old guy with sandals and a beard.  You are and have always been your own worst enemy, your own judge, and your own saviour.

From what I've seen from my own research, we are also part of All things, with reality being interconnected and infinite.  Separation is the illusion that causes us to behave and treat others the way we do.  Those that have attained such insight through meditation and personal experience will certainly agree with these statements and can easily be found practicing these concepts in their daily life; it is very hard to ignore such things when you've 'realized it' through your own personal experience.  I encourage everyone to do their own research and experimentation to determine whether this information on karmic action is true for you.  Don't take my word as truth; try it out and take a look for yourself!

Please feel free to make use all of this information for the well being of others and yourself.