"No matter how subtle the wizard, a knife between the shoulder blades will cramp his style"

Magic and skill can make a person seem invulnerable, but no amount of power or cunning can offer perfect protection in every situation. Even the most adept or refined wizard remains subject to the vulnerabilities of the flesh. The blade’s threat is direct, physical, and inescapably real, bypassing the abstractions and convolutions of spellcraft. The implication is that practical, straightforward action often triumphs over intricate machinations and subtle schemes, especially when the target becomes complacent or overly reliant on their abilities.

There’s also a nod towards the inevitability of human limitations. Arrogance or an overestimation of one's abilities leaves even the mighty exposed, especially to unexpected, mundane dangers. The wizard, master of the arcane and possessor of rarefied knowledge, can be rendered powerless by a simple, well-timed act. This evens the field between the extraordinary and the ordinary. No matter how much one achieves or how unique their talents, the simple realities of the world, violence, betrayal, mortality, remain ever-present.

Moreover, the phrase evokes the risks inherent in underestimating others. Wizards, or those in positions of perceived superiority, may forget that danger can come from humble or overlooked quarters. The knife in the back is often wielded by the unassuming, reminding us that power’s trappings do not guarantee safety or respect from all directions.

Brust’s words also suggest the importance of humility and caution, warning against the hubris of expertise. The greater the talent, the more one must guard against lapses in vigilance. Whether interpreted as a literal threat or a metaphor for the unpredictable consequences of life, the sentiment resonates: elaborate defenses and intricate strategies can be undone by a single, direct action. As such, power, especially when paired with subtlety, should not breed complacency or disregard for the simplest threats.