Rain on Roke may be drouth in Osskil, and a calm in the East Reach may be storm and ruin in the West

The principle that a wizard's actions have far-reaching consequences across Earthsea, expressed by the Master Summoner's warning that altering weather in one place can cause opposite effects elsewhere, and that all magic must serve knowledge and need to maintain the world's Equilibrium.

Origin and Statement

The rule was first articulated to Ged by the Master Summoner during his training at the School for Wizards on Roke. The Master Summoner, a stern and aged man hardened by the deep wizardry he taught, explained to his pupils why true wizards use spells only at need. He stated directly: "Rain on Roke may be drouth in Osskil, and a calm in the East Reach may be storm and ruin in the West, unless you know what you are about." This formulation makes explicit that the consequences of magical acts are not confined to the immediate location but ripple across the entire archipelago, potentially causing opposite effects in distant lands. The Master Summoner dealt with no illusion, only true magic—the summoning of real energies such as light, heat, and the force that draws the magnet—and he showed his pupils that to summon up earthly forces is to change the earth of which they are a part.

Connection to the Equilibrium

The rule is a direct expression of the fundamental concept of Equilibrium, the balance of the world that the true wizard knows and serves. The Master Hand had earlier taught Ged that a wizard's power of Changing and of Summoning can shake the balance of the world, and that it is most perilous: "It must follow knowledge, and serve need. To light a candle is to cast a shadow." The Master Summoner's warning about rain and drouth gives concrete, geographical form to this abstract principle. It demonstrates that the Equilibrium is not a static state but a dynamic web of cause and effect, where every magical intervention has a price paid somewhere else. The witch of Ten Alders, who knew nothing of the Balance and the Pattern, used her crafts for foolish and dubious ends, a contrast to the disciplined knowledge required of a true wizard.

Application and Significance

Ged himself experienced the truth of this rule during his voyage to Roke as a boy. When the ship Shadow was caught in a storm, the ship's master asked if Ged could abate the wind; Ged had to say no, and later, when the master asked if he had craft with iron to make the compass-needle point their way to Roke, Ged again had to say no. The master then decided to keep south, saying that only wizardry could bring them to Roke through that sea. Ged, however, saw a light to the west and insisted it was Roke Island, leading the ship to safety. This episode illustrates that even a young wizard must understand the limits of his power and the potential consequences of using it without full knowledge. The rule also underlies the Master Namer Kurremkarmerruk's teaching that the power to work magic sets the limits of that power: a mage can control only what is near him, what he can name exactly and wholly, because if it were not so, the wickedness of the powerful or the folly of the wise would long ago have sought to change what cannot be changed, and Equilibrium would fail. The rule is thus a cornerstone of Earthsea's magical ethics, teaching that true mastery lies not in the ability to do anything, but in the wisdom to know when and how to act, and to accept the far-reaching consequences of every spell.