Tales of the Traveler
A modern-day metaphor is necessary to explain the methods behind Arcane Magic. When a Wizard casts a spell, he’s manipulating reality by the same route as the Gods of Balance who created it—essentially, opening the console and entering a developer code. When a Wizard traces a glyph and recites an incantation over a ball of bat guano, he’s editing the matter to produce the desired effect.
A part of Arcane spellcasting is convincing the fabric of reality that the Wizard has the proper authorization to make the necessary changes; higher-level Wizards have learned more of the tricks necessary to do so, lending them the ability to cast more powerful spells.