Sigil magic as has been posted earlier has plenty to do with Chaos magik.
The power of the written word and intent lies at the core of the system.
I'd reccomend reading Liber Null by Peter Carroll source
It touches up on subjects that are sometimes harder to grasp by the conditioned western mind.
Magik works depending on what you expect it to be, and the results you seek.
A hypersigil is the visualization of intent made into the written symbolic, some people stop there, but the core of its power lies at the charging
Emotional power can be directed and thus able to charge the symbolic representation in the mind.
Sigil magic works, but in order to make it work one must commit to the proper training of the mindset.
Sigil magic can be dangerous in many ways, the most common problem encountered is that the symbol can become imprinted in the mind as an obsession,
you aim to imprint the sigil in the mind after its charged, and then forget about it, but not its intent, then one tries to remember the symbol and
when the mental image comes, all the emotional power one charged it with, comes forward like the water in a dam, powering the intent, and the
Many people charge sigils during orgasms, or during bed stays at hospitals, in fact it can be charged by every emotion, anger, love, excitement,
Its not the sigil, its the power one gets from it.
that is the magik inside.
Now , one must prepare the mind to exist in a world full of the possibility of intent, and of the inner workings of energy and human action.
Energy at its points of emanation has no polarity, that is given with work and with the intention, if you need to "harm" you charge it negatively,
if you wish to do "good" you charge it positively.
Polarities are the result of human thought, as in the natural order of things both spectrums are part of the same whole.
Be careful when practicing this art, as the results can be unexpected.
Read Liber Null, you'll find plenty of inspiration in that tome.