GURPS Alternate Earths

GURPS Alternate Earths is (as you may have guessed) a GURPS sourcebook (well, rather two books, but they're both covered here) about Alternate History -- or rather, alternate timelines which the characters may visit in one campaign, or live in from the start. Describes twelve timelines (six in each book) in loving detail.

The scenario "Centrum" inspired User:Max Sinister's Chaos Timeline.

All worlds:

 * Allohistorical Allusion
 * Alternate History Wank: The only thing changing is who (or what) is wanked high.
 * In Spite of a Nail
 * Richard Nixon the Used Car Salesman: Malcolm Little (Malcolm X) as VP of the rest-US in a world where the CSA successfully seceded. David Duke as POTUS in a world where The Nazis win World War II and the US become their fascist satellite. Jabir ibn Hayyan as a Roman chemist inventing mustard gas in 767. Swedish king Charles XII invading Britain. Roman emperor Heraclius founding a new empire in Africa after Constantinople falls. And Adolf Hitler ending up in an insane asylum painting more watercolors.
 * The sequel had some more of these. Alissa Rosenbaum writing novels about heroic rail builders in Nationalist Republican Russia. Japanese admiral Hiyoshimaru fighting European pirates for the Ming emperors. St. Bernhard of Clairvaux and St. Dominic de Guzman converting still-pagan Scandinavia to a somewhat different Christianity. Ibn Sina inventing calculus in 1006. Jan Masaryk elected Archon of an Austrian empire turned republic. And finally, Otakar Przemysl kicking out the Mongolian oppressors from the Holy Roman Empire in Centrum.
 * Spiritual Successor: Gurps Infinite Worlds.

Dixie:
Starts to diverge when filibusters take over Nicaragua and help the CSA become independent. Later, they will take over most of Mexico and Central America. The US are allied with Germany and help them win World War One.
 * Action Girl: In the US, women serve in all branches of the military.
 * Dark Action Girl: They also commit as many violent crimes as men do.
 * Alternate History Wank: For the CSA, Germany and arguably the US progressives and the united Indian republic.
 * Balkanize Me: The US (which takes over western Canada instead) and China
 * Cold War: USA vs CSA. In-universe called The Long Drum Roll.
 * Cool Train: The US have a lot of them, and they're faster than anywhere else.
 * Gauls With Grenades: Charles de Gaulle invents "guerre-eclair" (blitzkrieg)
 * Imperial Germany
 * John F. Kennedy: With Malcolm Little as his VP.
 * Shout-Out: The picture shows a CSA officer named "Butler" looking much like Clark Gable.
 * Southern Belle
 * Space Filling Empire: Germany owns about two thirds of Africa.
 * Straw Feminist: To Southrons, every Yankee woman is a man-hating harridan.
 * Zeppelins from Another World

Reich-5:
Diverges with the assassination of Franklin Delano Roosevelt. During the terms of Charles Lindbergh and the not-that-competent Nance Garner and Wallace, the US become politically split and polarized. Meanwhile, the nazis conquer half the world.
 * Alternate History Wank: Guess for whom.
 * Balkanize Me: The Soviet Union, which is no more.
 * Cool Train: kugelbahnen
 * Crapsack World
 * Imperial Japan
 * Nazi Germany
 * Nazis With Gnarly Weapons: Gnarlier than ever. In the present, their army has kevlar armor, tanks with railguns and neutron bomb howitzers.
 * Nuke'Em: The nazis didn't hesitate to level Denver, Dallas, St. Louis and Omaha in 1950 and Pittsburgh, Atlanta, San Antonio, Salt Lake City and Calgary in 1976 when the Americans started an uprising.
 * Shout-Out: The picture of the nazis deporting the Jews of Houston (happening in the 1980s) is based on the famous picture of the Warsaw Ghetto 1943. Except that they are wearing time-appropriate clothes - the little boy on the right has a baseball cap.
 * Space Filling Empire: Nazi Germany and Imperial Japan.
 * Those Wacky Nazis

Roma Aeterna:
Instead of the sinister Tiberius, a surviving Drusus takes over Rome after Augustus' death. During the following two millennia, Rome will expand, fall apart twice and reunite again and expand further. Their technology also develops, albeit not as fast as in our world.
 * Alternate History Wank: Rome, Rome and Rome again.
 * Balkanize Me: China (not by the Romans, though)
 * Eagle Land: Hesperia (Roman America) has a similar image.
 * The Glory That Was Rome: More glorious than ever!
 * Interfaith Smoothie: The Greco-Roman religion added American, Egyptian and Indian gods to their pantheon.
 * Jesus: May have been pardoned by the emperor, if he lived at all.
 * The Roman Empire
 * Space Filling Empire: Rome covers Europe, Africa north of the rainforest belt, the Middle East, Central Asia and India, most of South America and half of North America.
 * Steampunk: They have boxy, heavyweight steamcars.

Shikaku-Mon:
John Trastamara survives, hence no united Habsburg empire. The way history develops is... odd: Charles II and Louis XVI prevent revolutions which otherwise would have lead to more democracy and the creation of republics, and at the end, the whole democratic phase is somehow skipped, since the world transforms into a typical cyberpunkish society where nothing else counts but how rich you are.
 * Alternate History Wank: Japan, oh so much. Also, Sweden, France and Brazil which are the other three superpowers.
 * Balkanize Me: North America, (still) Germany
 * Cyberpunk
 * Japan Takes Over the World: More successful than ever. They manage to reign over two thirds of the world population!
 * Nuke'Em: Synarchist Sweden nukes four British cities when their pawns don't win the Civil War. As a result, 60% of Britain's population dies or emigrates.
 * Space Filling Empire: Japan, of course. How much? The eastern half of Asia (incl. India), the Pacific islands and Madagascar, and the western bit of North America.

Ezcalli:
The Carthaginians discover America, so the Old World diseases hit America two millennia earlier. The Roman Empire falls apart after Nero's been killed, and the various barbarians make sure Europe never recovers. Then the Aztecs start the Industrial Revolution.
 * Alternate History Wank: Mongols, Aztecs and Iroquois.
 * Balkanize Me: Western and Southern Europe, which were smashed too many times by barbarian hordes and part of the Mongol Empire for a long time.
 * For Want of a Nail: The reason Rome falls apart: Since the west European provinces have had access to New World staple crops for a long time, they're no longer dependent on Egyptian grain, so the economy and politics disintegrate fast.
 * In Spite of a Nail: Most Egregious example. The Aztec people still exists although history diverged more than two thousand years before them.
 * Made a Slave: Many Europeans who're sold to the Mongols and Aztecs then.
 * Space Filling Empire: The Mongol Empire, which still holds most of Eurasia.
 * Steampunk

Gernsback:
Nikola Tesla marries the daughter of J.P. Morgan, gains financial support to take out Edison, and can realize all his cool inventions.
 * Alternate History Wank: Science!
 * Cool Train: blitzbahnen
 * The Fifties: Even about twenty years later, the world is still much like this. (World War Two was avoided, the war which brought down the Soviet Union was shorter and more one-sided, thus less upsetting for the world.)
 * For Science!
 * I Want My Jetpack: And here, you get it!
 * Mad Scientist: They're very fitting for this world.
 * Nikola Tesla
 * Punk Punk: Diesel Punk overlapping with Atom Punk.
 * Technology Porn
 * Zeppelins from Another World
 * Zeppelins from Another World

Cornwallis:
Turgot manages to reform France, which prevents The French Revolution - and The American Revolution as well, since he won't support republicans against one fellow king. Only two centuries later, one great power (Russia) becomes the republican Dominate.
 * Alternate History Wank: For the great European monarchies.
 * Ayn Rand
 * Balkanize Me: Germany except for Prussia and Austria
 * Cool Train: The trains of Russia which impress less with speed and more with size.
 * Space Filling Empire: Britain and Spain (which kept their empires) and Russia (which includes Finland, Manchuria, Korea, Japan and Alaska - and was even bigger in the past)

Ming-3:
Ming China never scraps its fleet and starts to expand - first into Vietnam, later into Europe when their pirates attack... and there's no end, it seems...
 * Alternate History Wank: This time, it's China.
 * Just Before the End: The Emperor appears to have lost the Mandate of Heaven.
 * Space Filling Empire: China covers most of Eurasia (except for Russia, Persia and the Ottoman Empire), Australasia and half of the Americas and Africa.
 * Zeppelins from Another World

Midgard:
The Vikings manage to take Constantinople and capture the secret of Greek Fire. They manage to extend their rule over half of Europe, North America, Russia and Siberia.
 * Alternate History Wank: For Vikings.
 * Pirate: Everyone's doing it. Except for the Scandinavians (no surprise), the Gujerati, Yanomami, Japanese and many other people are also into it.

Caliph:
An eccentric Muslim scholar refutes the pagan Greek philosophers using rationalism. In combination with an Arab printing press, the Muslims take over the world and also develop science and technology way faster.
 * Alternate History Wank: Islam.
 * Awakening the Sleeping Giant/Sealed Badass in a Can: The whole timeline is presented as this with regards to the Infinite Worlds setting. Both Homeline and Centrum are, quite rightly, scared shitless of the prospect that Caliph might learn the Secret.
 * Space Filling Empire: The Bulgarian caliphate covers our Russia, southeastern Europe, and the north and west of North America / Talentis.
 * Technology Porn: Despite being in the 17th (Christian) century, they already have colonies in space, Nanotechnology and skyscrapers made of artificial diamonds.

Aeolus:
"The Divine wind" never happens, so Britain stays under the Stuarts and gradually becomes Catholic again.
 * Alternate History Wank: Averted; the setting gets too weird to say that any power is wanked up. For some times, the Bourbons.
 * The American Revolution, The French Revolution and Red October: The Austrian revolution is a mix of all of these, though it bears the greatest resemblance to the failed Revolutions of 1848.
 * The Fundamentalist: The American Covenant is a Puritan theocracy, bearing a strong resemblance to the Commonwealth of England.
 * In Spite of a Nail: Despite the short-term ascendancy of France due to England's weakness, France does not remain a dominant power in the world in the current era.
 * The Sound of Martial Music: The Hapsburg Empire dissolves on schedule, except that it also includes Russia, and Russia does not suffer the October Revolution.
 * We ARE Struggling Together!: Austria is a bit of a mess.
 * The Revolution Will Not Be Vilified: ...but the rebels know that they can't afford to hang separately, and currently the liberals are keeping everyone together and mostly civilized.

Centrum:
A more successful Angevin (Anglo-French) empire gradually takes over all the world. When the empire falls apart, a meritocracy centered on Terraustralis (Australia) rebuilds the empire. And then, they start discovering and conquering other timelines...
 * Alternate History Wank: Centrum. That is all.
 * Colony Drop: A rogue asteroid collided with Earth around the turn of the XXth century; this is what collapsed the previous empire.
 * The Rival: Centrum for Homeline