Included in the rulebook are a listing of general ways in which the modern world might experience an apocalypse, drawing on sources which include religious eschatology, current science, and popular fiction.

For instance, a plague scenario would not carry with it the same radiation dangers and physical damages to the infrastructure as would a nuclear war.

Given the collapse of society, the Wealth system from d20 Modern (which is based on a character's credit and standard of living as much as their cash on hand) no longer applies, and in its place the barter system is used.

In addition, due to the setting, certain items (such as ammunition) are worth more than they would be in a functioning society, while others (such as electronic entertainment) are worthless.

The new barter system prices all items according to their relative value in a post-apocalyptic setting, using Trade Units in place of dollars or Wealth DCs.