Each Final Fantasy has it's own type of summon, and that's what Guardian Forces (GFs) are to Final Fantasy VIII. As the name suggests, the purpose of a Guardian Force is to guard the characters. They provide a strong attacking power and, once summoned, receive any damage dealt to their junctioner until they are able to attack. Not only are they handy in tough battles but they are also entirely responsible for a characters abilities. Without one junctioned the only thing a character can do is attack.

To junction a GF to a character simply requires you giving it to them. GFs allow characters to use basic skills such as Magic, Item, GF, and Draw; and they also make it possible to junction magic to a character in order to strengthen certain aspects and make them more resistant to magic-casting foes.

Once aquired GFs can learn new, more helpful skills. There are skills which boost stats such as Magic or HP, those which allow you to refine unwanted magic or items into more useful things, and even a skill which stops you from encountering enemies (which is great if you want to get somewhere fast without having a bunch of weak monsters attack you on the way).

Squall recieves two GFs right off the bat: Shiva and Quezacotl. As the game progresses, he has the option to aquire more. There are many ways to obtain GFs, some must be found and fought, some must be awoken from mysterious items, and some must be drawn from other enemies. But in the end, they are worth all of the trouble that you go to in order to get them because they are such an asset in battle.

Guardian Forces are not just emotionless war-monsters, but rather a lot more like pets. The more that they like a character, the faster they'll come when called. This is known as compatibility. After a GF is summoned, there is a waiting period as the GF prepares to appear in battle. The higher the compatability, the shorter the waiting period. Compatibility is raised simply by having a character use a GF in battle. The more that character summons that GF, the more it will like them. Typically, however, if a character has a high compatibility with an ice type GF, then he or she will be hated by the fire type ones. This goes for all elements: The compatibility of a GF of a certain element will rise or fall depending on how much the character summons a GF of opposite element. The highest compatibility is 1000, while the lowest is 0.

Of course there is a sacrifice that one must make in using a GF, and that sacrifice is their memories. When a GF is junctioned, it makes it's own place inside the brain of the person who it is junctioned to. The area in which they do this also happens to be where memories are stored. The memories that are lost are those which are not thought about, or remembered, on a regular basis. It is the GF, for example, which causes Squall, Selphie, Zell, Quistis, Seifer, and Irvine to forget their childhood in the orphanage.

Below is a list of the regular GFs that can be attained throughout the game. Many of them are based on mythological creatures.

There are also some special GFs which you may obtain:

I have scanned in some tables from the Brady Games Official Final Fantasy VIII Strategy Guide. They contain helpful information about GF's and their abilities. All credit for these goes to Brady Games.