Red Magic is the magic of War.
Peter Carroll has a few interesting points to make about the nature of war.
1) War has rules.
There are always to war. When parties have differing understanding of those rules it is often very scandalous. Matter such as the treatment of prisoners, collateral damage, and acceptable losses all play into this. Standard modes of conduct and strategy may evolve over time, but are still generally accepted.
2) War has set objectives
War is a means to gain control over resources, be it oil, land, political power, money, or even reputation. There are plenty of examples where those objectives may not be clearly spelled out or apparent, but they are there.
The point of war is to intimidate your opposition and force them out of “fight” mode and into “flight” mode. It is a direct power contest in which you force your opponent to submit to your authority. Ultimately, your opponent should become a resource to you.
Strictly speaking, genocide is not war.
The most effective war is one in which you can convince your opponent that it isn’t worth the effort to resist you.
3) Morale is vital to war
The confidence and aggression of strong moral are very often the deciding factors in most military conflicts. Much of the training and esprit de corps in the military is designed to boost morale. Getting yourself worked up and into an aggressive and dominant state of mind is very important to victory.
So how does this translate to magical action?
Firstly, red gnosis deals with improving morale and increasing aggressive and dominant posturing. Need to build endurance or present an intimidating glamor? Need the energy and momentum to engage in a conflict and sustain yourself through it? Need to prepare yourself for overcoming a major obstacle? Red gnosis will help you.
Red gnosis also deal with combat magic. Red combat magic is usually about theater. It is about intimidation and inducing fear and paranoia in the target. Red magic curses are usually thrown openly and publicly. This is the kind of magic where the bloody poppet is nailed to someone’s door, or they receive a strange sigil in the mail, or where you otherwise make a grand production about the pain they are about to endure.
Subtler means can also be employed, with the source of the curse being concealed but its effects being more known. This approach is more similar to the entropy of Black magic (which will be discussed later), but still has the goal of intimidating and dominating the target rather than a lethal result.
Red gnosis is generally associated with some kind of anger or rage, or other similar emotions. Images and props such as spears and swords are useful, and aggressive drumming helps as well. Fire is good as well.
But the best way to win a war is to never have to fight one:
[T]he real skill of red magic is to be able to present such an overwhelming glamor of personal vitality, morale, and potential for aggression that the exercise if combat magic is never required.