The Sundered Throne
Rolls are often modified by a number of factors. It’s easier to sneak when it’s dark, it’s harder to drive when it’s raining, attacking with a gun does more damage than a fist.
Modifiers are simply an addition to or subtraction from the character’s die pool. Darkness might add +2 dice to a sneak attempt, rain might subtract 2 dice from a driving attempt. Guns and other equipment add some number to the roll based on how good they are.
Most modifiers range from 1 to 3, either positive or negative.
It’s possible for a roll to have both positive and negative modifiers. One simply adds up all the relevant modifiers to get the final total of dice added or subtracted and then modifies the dice pool.
A skill can have one or more specialties. Perhaps a character is better with swords than just any weapon, and thus has a Weaponry skill specialty of Swords. Maybe they are better at fast-talking, and has a Subterfuge skill specialty of that name.
Each specialty adds 1 die when the character employs the skill in a way that relates to that specialty. Multiple specialties can be purchased for a single skill, but they must be for different situations, they do not stack.
Specialties are a great way to customize a character. The two main uses are to boost a low ranked skill in one area, or to give a character a really impressive specialty for a high ranked skill.