Palladium Books

Rifts

Hundreds of years in the future, when earth is in a golden age of technology, a nuclear war starts. The mass deaths release PPE into the Ley Lines of the world on a level that tears open rifts which are the drains and spouts of magic energy at ley line intersections. Tearing open rifts is bad, and beings from other dimensions invade our world and make it as alien as our nightmares allows us to believe.

The invasion brings on a dark age where the technologies and comforts of the new golden age are replaced with hardship, slavery, wilderness, and most importantly, conflict.

Most games are run around 100 PA (Post Apocalypse), or roughly the year 2300 AD.  Humanity is just beginning to emerge from this second dark age.  City states dominate the map, and nations are largly a thing of the past.  The greatest of city states can be multiple fortified archologies, surrounded by swarms of shanty towns known as burbs.  The smallest could be a wood walled palisade with a single guy and a laser rifle.

High technology exists along side low technology from hundreds of years ago, which exists alongside psionics and magic.  That means Dragons and elves using swords and bows and magic, might face Super soldiers with laser rifles and giant robots.  Towns might have running water but no electricity, or be lit by magic, but not have useable irrigation. 

Resources:

Rifts on Wikipedia A fairly thorough description of the game.

Palladium Games Official Site

Palladium Books Wiki Entry

Games:

RIFTS games run