now revised, and with a new introduction by the author

Pop anthropologists claim, oh, happy refrain,
man's defined by tools.
Tools help us abide
ol'entropy's tide,
But even
they obey the rules!
The Practice Effect

revised and with a new introduction, 2020

DAVID BRIN's Practice Effect cover for revised edition

original Bantam 1984 edition cover

DAVID BRIN's Practice Effect cover for 1984 original edition

does practice make perfect?

"He tried to remember a few facts from the linguistics course he had taken in college in order to get out of the infamous Professor LaBelle's English 7. There were a few sounds, he had learned, that were nearly universal in meaning among human beings. Anthropologists used to use them at the beginning of contact with newly discovered tribes. He swallowed, then ventured one of them. 'Huh?' he said." — The Practice Effect

Physicist Dennis Nuel was the first human to probe the strange realms called anomaly worlds — alternate universes where the laws of science were unpredictably changed.

But the world Dennis discovered seemed almost like our own — with one perplexing difference. To his astonishment, he was hailed as a wizard and found himself fighting beside a beautiful woman with strange powers against a mysterious warlord as he struggles to solve the riddle of this baffling world.

Read the first 2 chapters online, or scroll down to purchase THE PRACTICE EFFECT.

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more about The Practice Effect

practicing puns

The chapter titles for The Practice Effect are jokes, mostly puns. In order, with explanations:

  • Sooee Generis (like 'Sui Generis' but with the pig-caller's noise)
  • Cogito, Ergo Tutti Fruitti (I think, therefore tutti fruitti)
  • Nom de Terre (tr. 'name of the land' but in the context of the chapter a play on 'Nom de Guerre')
  • The Best Way to Carnegie Hall (... is practice)
  • Transom Dental (a play on 'transcendental')
  • Ballon d'Essai (tr. 'trial balloon')
  • Pundit Nero (Pandit Nehru, first Prime Minister of India)
  • Eurekaarrgh (a more accurate variation of 'eureka')
  • Discus Jestus (majesty disc)
  • Sic Biscuitus Disintegratum (or 'this is how the cookie crumbles')
  • Et Two Toots (or 'Et tu, Brute?')
  • Semper Ubi Sub Ubi (tr. 'always where under where' but in the context of the chapter, 'always wear underwear')

  • foreign-language editions

    Here are some of the covers of The Practice Effect's foreign and foreign-language publications.

    The Practice Effect's foreign editions

    can you 'practice'?

    Want to try out the 'practice effect' in this universe? Take a look at this page evaluating agile vs. scrum vs. waterfall vs. kanban.

    The Practice Effect in the world

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  • film & media queries

    Queries about film or media rights to any DAVID BRIN books or stories can be addressed to his film agent:
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    (with cc: to David Brin)

    The Practice Effect reviews

    Publishers Weekly

    "Reminiscent of the freewheeling, high-spirited alternate world novels of the '40s ... Lively, outlandish and entertaining." review

    "David Brin's The Practice Effect is the reason I began reading everything I could find by this author. Brin has taken a single premise (what if one of the laws of thermodynamics were repealed?), and woven it into a clever tale of a world of practical magic.... Further, the central concept of the novel makes explicit the crucial difference between creators and users."

    Isaac Asimov's Science Fiction Magazine

    "High spirits and inventiveness ... Dennis's adventures, which can only be called rollicking, are legion."

    Goodreads community review

    "It started off feeling a lot like John Carter from A Princess of Mars meets A Connecticut Yankee in King Arthur's Court. By the end I added a good dose of the movie Speed to the mix. That pretty much sums it up. Except for one thing that made it exceptional — the practice effect. I love when an author comes up with a really original idea that would deeply influence how things turned out in the world and follows it through. It turned a really basic and frequently used idea, that of the modern man or scientist who finds himself in a society that has little or no technology, and turned it into something interesting."

    No Wasted Ink review

    "This is a clear forerunner to his development of science to propel the plot in his later novels. The concept of the practice effect itself makes this novel one that you should take a look at in addition to Brin's other more well known works. To me it was as if the world was a character all unto itself. I kept wanting to see more of how the practice effect changed the lives of these people. Although I read this novel many years ago, I have never forgotten it and I feel it is a work that needs to be called attention to. Otherwise, you might miss out on a truly unique science fiction experience." customer review

    "Gee, not every SF book has to be a deep exploration of the limits of the genre. Sometimes you just like to kick back and enjoy yourself. This is exactly what this book is, and it's a great read, fast and fun at the same time, while still throwing up some interesting concepts."

    Poul Anderson

    "A delightful, often very witty story, with the underlying thoughtfulness we expect from David Brin."

    a brief intro to science fiction author DAVID BRIN

    To learn more, visit his books page, or see his "about me" page or detailed biography.

    DAVID BRIN author


    David Brin's science fiction novels have been New York Times Bestsellers, winning multiple Hugo, Nebula and other awards. At least a dozen have been translated into more than twenty languages. They range from bold and prophetic explorations of our near-future to Brin's Uplift series, envisioning galactic issues of sapience and destiny (and star-faring dolphins!). Learn More

    shorter fiction

    Short stories and novellas have different rhythms and artistic flavor, and Brin's short stories and novellas, several of which earned Hugo and other awards, exploit that difference to explore a wider range of real and vividly speculative ideas. Many have been selected for anthologies and reprints, and most have been published in anthology form. Learn More

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    David Brin's Ph.D in Physics from the University of California at San Diego (the lab of nobelist Hannes Alfven) followed a masters in optics and an undergraduate degree in astrophysics from Caltech. Every science show that depicts a comet now portrays the model developed in Brin's PhD research. Learn More

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    Brin speaks plausibly and entertainingly about trends in technology and society to audiences willing to confront the challenges that our rambunctious civilization will face in the decades ahead. He also talks about the field of science fiction, especially in relation to his own novels and stories. To date he has presented at more than 200 meetings, conferences, corporate retreats and other gatherings.Learn More

    future/tech advisor

    Brin advises corporations and governmental and private defense- and security-related agencies about information-age issues, scientific trends, future social and political trends, and education. Urban Developer Magazine named him one of four World's Best Futurists, and he was appraised as "#1 influencer" in Onalytica's Top 100 report of Artificial Intelligence influencers, brands & publications. Past consultations include Google, Microsoft, Procter & Gamble, and many others. Learn More

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    reviews and recommendations

    Vernor Vinge

    "More than any writer I know, David Brin can take scary, important problems and turn them sideways, revealing wonderful opportunities. This talent shows strongly in Kiln People, a novel which is deep and insightful and often hilarious, all at the same time."

    praise for Heart of the Comet

    "A magnificent effort ... their story gets better, and better, and better."
    — Locus

    praise for Earth

    "Brin is a physicist of note who has been a NASA consultant, and he knows how to turn the abstractions of particle physics into high adventure.... He excels at the essential craft of the page-turner, which is to devise an elegantly knotted plot that yields a richly variegated succession of high-impact adventures undergone by an array of believably heroic characters."
    — Thomas M. Disch,

    praise for Sundiver

    "The original Progenitors have long disappeared, and the intergalactic search for relics of their presence, along with the conflicts generated by humanity's asserted uniqueness, shapes much of the sequence, which Brin enlivens throughout with exceedingly clever depictions of a wide range of Alien species."
    — John Clute, The Encyclopedia of Science Fiction