Brainstorming Alternate History
But in the meantime... I've been reading heaps of alternate and secret history stuff lately (Guns of the South, Best Alternate History Stories of the 20th Century, and Alternate Presidencies), and they sparked an idea about how to brainstorm alternate history plotlines.
Take a sheet of paper and place it landscape format in from of you. In the middle of the sheet, write a sentence describing some well known historical event that might have turned out differently, for example: the Union wins the Civil war, Constantinople falls, Ceasar crosses the Rubicon.
Now above it write some much less significant historical even that nevertheless has an impact on the event below it. Examples include: Stonewall Jackson is shot and killed by friendly fire.
Below it write some general consequence on the shape and form of our world that results from the historical event in the center. Examples might include: Slavery is eliminated from North America, Rome becomes and empire. Connect the three by arrows showing the (loosely) causal connection.
Now to the right and left of the top item of the page write two alternate possibilities for your first historical event. For example: Stonewall Jackson is wounded and turns to politics, Stonewall Jackson is not shot and lives to participate in the Battle of Gettysburg.
Next, do the same with the event in the middle of that page, but instead of one possibility, write two possibilities on each side. Make them increasingly radical. For example: right side -- The Civil War lasts another four years, The South wins the Civil War. Left side -- The Union Wins the Civil war and Lincoln is never assassinated, The Union Wins the Civil War but Southern Generals retreat into South America to set up a shadow government.
Finally, so the same on the bottom of the page but write three possibilities on each side. Feel free to get wild and crazy with your outermost events. Armies of Abraham Lincoln Clones, Nazis landing on the moon, or a Roman Empire that lasts until 1945 are all great examples.
Now connect up your alternate possibilities. Each possibility connects to the two possibilities underneath it to the right and left. For example, the rightmost option at the top of the page connects to the two options to the right of center on the next level down. These connections represent alternate timelines.
You now have an alternate history "what if" tree. You can take a timeline and refine it to use as a plot or setting for a game. You might even use this tree as the basis of a cross-time history altering battle between future agents of competing interests with one faction trying to push the tree right or left while another tries to bring it back to the middle. For some really high weirdness, write an alternate timeline down the middle and put the "real" history timeline down one of the wings.
This all has something to do with Mathematica, a design problem I can't stop thinking about, but am not yet remotely ready to tackle.
Here's another exercise. Instead of Alternate History, do a Secret History. This is a history that is outwardly indistinguishable from (and possibly identical to) our own, but which hides a great secret that changes the meaning of history. Many storylines involving agents trying to "set the past right" are technically secret history.