System Reference Document

DIFFICULTY MODIFIERS (DM) 

Not all tasks are created equal, and that is where Difficulty Modifiers come into play, when making Skill Tests andAttribute Checks. A Difficulty Modifier (DM) is a +/- adjustment applied to the Attribute being checked or the Linked Attribute of the Skill being tested. 

Difficulty

Difficulty Modifier

Very Easy

+4

Easy

+2

Hard

-2 (Min. 2)

Crushingly Hard

-4 (Min. 2)