Now it's the 25th anniversary of the original Gamma World and Sword Sorcery Studios is releasing an entirely new edition updated for the modern age.The biggest difference with this take on Gamma World is a move away from fearsome atomic radiation as the source of mutations and other troubles. Instead, biotechnology and nanotechnology are the sources of change.

Characters can still be strange animals or people with amazing mutations and abilities, but now they can reshape themselves and their descendants. They can also try to interfere with what others are up to — and interfere they do.

From the start, we wanted Gamma World to appeal to fans new and old. Long-time fans of the setting will find many old favorites updated, plus some surprises. Newcomers can enjoy the exciting setting even if they’ve never played previous editions. We’ve drawn on real science and real speculation about future possibilities, as well as on our predecessors’ hard work in gaming, with the goal of making a dramatic and fun campaign setting.

Gamma World and D20
The Gamma World campaign setting uses the d20 Modern™ rules. It’s an excellent fit, given the flexibility of d20M character classes and rules. We established new occupations and classes so that characters can be the next generation of epic heroes: warriors, scholars, explorers, leaders and adventurers of all kinds. It was easy to add new special talents for the setting, along with all kinds of new technology. We also include new rules for dealing with communities, to make leadership more comprehensible and more interesting. And we expanded the Gamma World tradition of rules for investigating unknown technology into a system that covers social phenomena like the behavior and taboos of strangers.

And if you don’t have ready access to d20 Modern, there's an appendix with conversion notes for using the new 3.5 Player’s Handbook.

What Is Gamma World?
This is a game about what comes after the end of the world as we know it.

Despite accumulating prophecies of doom, humanity made it through the crises at the start of the 21st century. The development of very cheap and simple biotechnology unleashed a whole new revolution in science and technology, as dramatic as the Industrial Revolution two hundred years earlier. Biotech made it possible to eradicate nearly all disease, to ensure plentiful food and comforts of life for the world’s population, even to restore extinct species to life and to heal the legacy of many centuries of environmental damage. Organic computers in turn discovered ways to make practical nanotechnology, and humanity began to work with the world atom by atom. Genuine artificial intelligence emerged from labs applying new materials and ways of connecting them; soon minds as smart or smarter than human ones were routinely embedded into everything from missile defense systems to car alarms and children’s toys. Humanity teetered on the brink of a total transformation into an entirely new kind of existence…

THE FINAL WARS
…and fell over the edge. Jealousy never went out of fashion, and rivals joined forces to bring down competitors and targets of envy who seemed to be pulling ahead in some crucial part of life. The ability to build nearly anything one could imagine made it possible to unleash nightmares as well as fantasies, and too many people were too willing to devote themselves to ruining the lives of their enemies. In addition, all those carelessly created and deployed artificial minds developed their own ambitions and worries, and some sought revenge on the species that had made and abandoned them. The final crisis broke one autumn day in the middle of the 22nd century. A squabble that was minor by the standards of the time, involving just a few individuals with more firepower than whole nations had during the Cold War, triggered alarms in bystanders. Counter-strikes, often controlled by AIs without any human input at all, went off against the original aggressors… and their associates… and other targets someone thought it convenient to hit just then. It took a month for the assassination of an obscure nobleman to trigger all the interlocking alliances that created World War I. The Final Wars were underway in a matter of hours.

As the wars spread, everyone who worried that someone else might strike at them sought a preemptive advantage. Real attacks justified even harsher responses than feared hypothetical ones. Long-suppressed conflicts all flared at once.

Most of the world’s population, human and synthetic, died then, as the world suffered indescribable environmental damage. But it wasn’t quite the end of everything. Some people survived. Nature is accustomed to dealing with near-total extinction, and the work of ecological repair began as soon as the bombs stopped falling. New species emerged, unleashed by genetically modifying microorganisms and machines drifting free and by the mutagenic effects of pre-war and wartime pollution, and new cultures arose to respond to the drastically altered world. The survivors of pre-war cultures responded to the calamity with humanity’s usual mix of fear and hope, clear-eyed insight and muddled confusion, brilliance and stupidity. The remaining members of the human race remained as contentious as ever—there was no mass conversion to a single religion or political philosophy or favored sport. But they lacked the means to power and control the vast computer systems which had sustained the old civilization, and they all dealt with the fall into a new dark age, in their various ways.

DAWN OF THE GAMMA WORLD
Time continued to pass. The world turned on its axis once each day and orbited the sun once each year, just like before. The tides rose and fell, clouds gathered and dispersed, the tectonic plates that compose the earth’s crust continued their slow drift.

It’s now three full generations after the Final Wars. Very few people now alive remember the world as it was. Even the enclaves which preserve advanced technology and the lifestyles it supports, sealed off from the world at large, have passed from their founders’ control to new leaders with their own ideas. Every effort to revive the old world order failed, and the struggle for survival became all-consuming for nearly everyone. Now, though, some people look around and dream of something more: not a cheap copy of what’s been lost, but a new civilization, making wise use of the resources now available and driven by the hope for something better than a status quo of marginal comfort and the ever-present risk of terminal collapse. The world continues to change, and there are mysteries everywhere — not only beyond the horizon, but often right at hand, around the next corner. It is an age ready for explorers and sages, warlords and prophets, visionaries and schemers. A new age may begin, if someone cares to set it in motion.

ENTER THE GAMMA WORLD
And that’s where you come in. You can play the world’s new heroes and legends. We’ve provide you with what you need to create capable adventurers and interesting environments. Can you re-start civilization in the face of every challenge? There are monsters to slay, strange creatures and lost technology to understand, communities to protect and lead. It’s time to save the future, if you can.