Chaos is not in itself, a system or philosophy. It is rather an attitude that one applies to one's magic and philosophy. It is the basis for all magic, as it is the primal creative force. A Chaos Magician learns a variety of magical techniques, usually as many as s/he can gain access to, but sees beyond the systems and dogmas to the physics behind the magical force and uses whatever methods are appealing to him/herself. Chaos does not come with a specific Grimoire or even a prescribed set of ethics.
For this reason, it has been dubbed "left hand path" by some who choose not to understand that which is beyond their own chosen path.
There is no set of specific spells that are considered to be `Chaos Magic spells'. A Chaos Magician will use the same spells as those of other paths, or those of his/ her own making. Any and all methods and information are valid, the only requirement is that it works. Mastering the role of the sub-conscious mind in magical operations is the crux of it, and is the road to that end.
Anyone who has participated in a successful ritual has experienced some degree of the `high' that this state induces.