The measure of a test’s difficulty is reflected in its modifiers. Modifiers are adjustments made to the target number (not the roll), either raising or lowering it. A test of average difficulty will have no modifiers, whereas actions that are easier will have positive modifiers (raising the target number, making success more likely) and harder actions
will have negative modifiers (lowering the target number, making success less likely). It is the gamemaster’s job to determine if a particular test is harder or easier than normal and to what degree and to then apply the appropriate modifier. Other factors might also play a role in a test, applying additional modifiers aside from the test’s general level of difficulty.
These factors include the environment, equipment (or lack thereof), and the health of the character, among other things. The character might be using superior tools, working in poor conditions, or even wounded, and each of these factors must be taken into account, applying additional modifiers to the target number and adjusting the likelihood of success or failure. For simplicity, modifiers are applied in multiples of 10 and come in three levels of severity: Minor (+/–10), Moderate (+/–20), and Major (+/–30). Any number of modifiers apply as the gamemaster deems appropriate, but the cumulative modifiers may not exceed +/–60.