First, once again, our foundational rule as always: in real world occultism, it's EASY to find occult knowledge, it's HARD to find anyone who actually engages in practicing it, because 90% of the people in the scene are armchair-magicians or posers or frauds or dilettantes, anything but people who actually work at doing magick.
One way to tell a faker from someone (potentially) genuine is to look at the magical accoutrements they use. Are they going around with a fancy-looking crystal-encrusted rune-marked perfectly-straight wand that may have been store-bought or ordered from Etsy? They're 99% likely to be frauds (that last percentage point is just because there just may be some serious magician who has gotten to the level of occult talent that he doesn't have to give a fuck what he does, and also doesn't care about being mistaken for a poser).
Are they using an wooden wand they clearly crafted themselves (or maybe even a metal wand they smelted themselves) with tremendous attention to qabbalistic correspondences? There's maybe only a 70% chance they're fakers. Why so high still, you ask, given that clearly it's a case of someone doing something?
For a very good reason: collecting (or even making) the accoutrements of magick does not make you a magician. There are lots of people who, in addition to collecting an enormous library of occult grimoires (the likes of which would have made John Dee piss his robe with envy), also collect or even carefully craft the magical tools, the wand, the lamp, the altar, paint a ritual room, carefully carve enochian tables using authentic medieval methods, commission gold-trimmed robes and the most expensive frankincense, and so on, but then don't actually do a damn thing with them all. Sort of like the guy who collects hundreds of RPG books and owns 17 pounds of dice (and probably posts like crazy on internet forums), but never 'has the time' to actually play.
Finally, if your possible magician's wand is just a stick, there's maybe a 90% chance of being a faker. Or better put, this is the scenario where the person in question is either going to be a total faker/poser/newbie of no value (probably claiming they're a 'chaos magician'), or a really impressively competent magician. The guys in the middle, the eager-beavers trying hard to figure out how to do all this stuff, will become obsessive about trying to get every last technical detail right, following Golden Dawn rules or following the precise (often ridiculously difficult) instructions found in medieval grimoires. This is important, for the discipline needed to learn. Thing is, when you get to the level of adept suddenly all those tools have been largely internalized, as have the correspondences. And at that point you can do magick equally well with the simplest of tools, or even whatever objects you have at hand. Aleister Crowley famously once did a magical operation halfway up a mountain using the stuff from his climbing gear.
Which brings us to the use of magical talismans. A talisman is a term for some kind of physical object that was used in a magical ritual to imbue it with some kind of particular 'magical link' to an archetypal force, to achieve a specific purpose. This is used to create a more lasting effect or for purposes you know you're going to need over and over again.
For talismans, the rule is exactly the same as with all the other magical tools and equipment: if it's all fancy and clearly store-bought it's almost certainly useless. If it's meticulously made (usually, in the case of western magical talismans, at least, out of some type of metal) with carved hebrew characters or sigils, there's a (high) chance it's bullshit and a (small) chance it might be the work of some intermediate magician (and thus reflective of either a successful or unsuccessful operation).
What about the advanced ones? Well, consider this: the most powerful of all the medieval grimoires (the Book of the Sacred Magic of Abra-Melin the Mage) has a set of talismans in it (and guidelines for creating them or others of the same kind) that are so dangerous that they can only be used by Adepts. These are the most powerful and effective talismans in western magick. And what do they look like?
Like a slip of paper with a square full of letters on it. Something that could be mistaken for a doodle, or an incoherent crossword.
The most advanced magicians usually make talismans that don't look like talismans at all.
They can only do this effectively, again, because as adepts they have completely internalized the power of Symbol. The reason you need, when you're starting out, to follow the rules (and the reason why most rule-breaking 'chaos magicians' are kind of crappy in spite of tending to actually try to do magick more often than most other types of magicians) is because these outward objects end up acting as powerful symbolic aids in connecting your conscious mind to the True Will, and from there to those Archetypal Forces you're trying to work with. This is another important rule of 'real magick': the more simple anything to do with magick is, the more advanced of a magician you have to be to do it right. The most complex rituals, though technically difficult, are the ones you'll be most likely to succeed at if you're a hard-working beginner. The "simplest" stuff (in terms of technical complexity) requires that you already have a strong background in the practice of daily preliminary disciplines and have internalized the symbols through a series of personal initiations and 'ordeals' (that is, shifts in your level of consciousness). Trying to 'skip ahead' to the stuff that looks easier will usually just leave you in a dead end.
In a modern-occult RPG, you could have some rumor going around about some serious magician, said to own a talisman of an aspect of Jupiter that was revealed to him during astral working while he was working with a secret book (the "Second Book of Abramelin", which had been dictated to him by his Augoeides while working adept-level ritual). This facet of Jupiter (who called himself Jupiter Celestion) governed work, discipline, labor, planning, enjoyment (in and of labor), and the creation of the material world (that last aspect would be particularly interesting, as it would permit the magician to manipulate the most basic level of material reality). Celestion endowed this magician with a talisman that, when held and activated, would draw material wealth, never undeserved wealth but in the form of easy opportunities to labor at what one would most love doing.
Now, the PCs might wish to try to obtain this talisman, in essence cheating their way to magical power (that never ends well, mind you, but maybe they're stupid or something), so they try to find this guy's talisman. They're looking for some kind of metal disk (tin, probably, since that's the qabalistic metal of Jupiter) with Jupiter-related symbols on it, or some other kind of fancy object. They fail to find it, maybe get caught. Imagine their surprise when the magician chuckles at their naivete and reveals the reason they came up empty-handed: they were looking for some fancy piece of jewelry, but it turns out the Talisman of Jupiter Celestion is an 25 cent piece.
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