Each time you start a new campaign in Afterworld, Paradox’s upcoming post-apocalyptic grand strategy game, a tiny virtual historian cracks their knuckles and gets to work writing a new 200-year history for what happened to North America in the dying days of the great war. They will decide where the great powers fired their nuclear-tipped missiles, where they released their clouds of flesh-eating nanites, where they dropped their lung-bubbling chemical weapons, and they will decide who survived and who died.…