Arcane magic flows from one of the Five Founts of magic, located on Stormfell. This magic originates in the Elemental Chaos, its form close to raw chaos. As the energy travels through the Founts, it experiences a purification of sorts. The Founts act like filters and cleanse the magic, removing elements detrimental to mortal spellcasters. Any magic that comes through the Founts is known as arcane. Practitioners of arcane magic include bards, wizards, sorcerers, warlocks, and similar individuals. If a magic-user draws magic directly from the Elemental Chaos, avoiding the Five Founts, he is tapping into blight magic.
For wizards, arcane magic depends upon complex memorization, ritual, incantation, precise gestures, material components, and reagents. Other arcane spellcasters still draw magic through the Five Founts, but they control their magic in different ways, and always with some sort of focus. Whereas wizards utilize memorization and ritual, bards, for example, use music, rhythm, and words to focus their spells. Sorcerers, on the other hand, concentrate on a unique element locked within their blood and use that to focus their magic.
Of all arcane spellcasters, warlocks represent the most unusual. Warlocks still access arcane magic through one or more of the Five Founts, but their focus comes via an outside power by means of a pact. Without the pact, a warlock loses all ability to control magic. Their pact grants them abilities and talents that come only to a wizard, for example, after long years of study and practice, or to a sorcerer through natural talent. Regardless of what pact a warlock observes, his arcane magic still originates from the Five Founts, and he thus avoids the corrupting influences of the Blight.
By definition, any spellcaster tapping into arcane magic draws it from one or more of the Five Founts. Put another way, if the magic is called arcane, it comes from the Founts. Wizards are only taught how to access magic through the Founts – their training and mental conditioning essentially prevents them from calling on Blight magic. A wizard must overcome substantial barriers in his mind and body before he can tap into the Blight. For the most part, tapping directly into the Blight demands special training. For other arcane spellcasters that acquire magic through other means (such as a pact or from natural talent), casting blight magic still requires direct intent, willingly making the choice, and (quite often) a sacrifice of some sort. Although hedge mages, witches, and some sorcerers may touch upon the blight without truly understanding the danger, for the most part it is extremely rare for a spellcaster individual to tap inadvertently into the Blight.