The Rule of Maximum Drek

Taken from ShadowRun, this rule simply resolves any math complex enough to leave fractions in a system based on whole numbers:

Round in the direction that goes worst for the Player in question.

More generally, on an Internet where a lot of people don’t even seem to know how the phrase originated, this principle translates to: “Assume that whichever is going to cause you the most problems is true; plan accordingly.”

In other words, fractions round down when you’re figuring out how much cash (in APs) the heroes managed to put together, and up when you’re figuring out how many Hero Points that new Gadget is going to cost someone.

Fortunately, it doesn’t come up too terribly often, and it applies just as unpleasantly to the villains.