Simply put, Hedge Magic is totally up to the Narrator. Hedge Magic is the magic of the Empire City Epoch. It is published in countless volumes of witchcraft and ritual magic, most of which are meaningless, mumbo-jumbo crap. Whether or not these things actually work... Well, according to most of "civilized" society: No, it doesn't. However, enough people believe in the possibility of magic, and even more practice it, that some effect may be elicited through these "modern" rituals. The limitation of Hedge Magic is that it is inundated by mundane reality, and therefore may only be used to alter probability in unremarkable ways.
For Example:Bobby wants a job so he casts the "Neidajawb" incantation on page 57 of his Cute Lil' Book 'o' Spells. The effect of his strong willpower bends the probability in his favor, but only if he goes out and looks for a job. He does indeed find work. The spell either worked or he simply got a break through virtue of the power of positive thinking.
Hedge Magic may not be used for direct attacks nor can it defend against the effects of High Magic, below. The Narrator may set variable opposition for an Overcome or Create Advantage action or may simply declare that "there doesn't seem to be any effect", at their discretion.
True Magic, Thaumaturgy, Sorcery... by any name the power remains the same. This is the fireball-slinging, corpse-raising, item enchanting, mage armoring kind of magic found in high fantasy settings. Some of this information will be very similar to that found in Powers, especially for practitioners of The Way (below), but details may differ and in either case gathering all of the information regarding magic use in a single section simplifies the lives of both wizardry PCs and their Narrators.
The Art is ritual magic and is, potentially, far more potent than The Way. What The Art lacks in immediacy, it makes up for in impressiveness. Enchantments, summoning, binding, blessing, cursing, dispelling and such effects are the arena of The Art. Unlike The Way, The Art consists of spells and arcane knowledge, requires magical ingredients, special incantations, and many of the trappings of magic with which one may already be familiar such as cauldrons, wands, and circles of power.
The Way is the skill of influencing the primal forces behind magic to produce an almost unlimited variety of effects. The Way is often referred to as the Warrior's Way, as magic-users who specialize in this more immediate application of magic tend to lean towards combative lifestyles. The Way has no Spells; it instead features Techniques, which are the skills necessary to influence the forces behind magic to produce the desired effect. While not as dramatically powerful as The Art, The Way is immediately and personally potent.