Identify the Modifiers That Apply and Roll Your d20 Dice Pool

Start by identifying all the relevant modifiers, bonuses and penalties that apply to the roll. A modifier can be either positive or negative, but a bonus is always positive and a penalty is always negative.

Nearly all checks allow you to add an attribute modifier to the roll. An attribute modifier represents your raw capabilities and is derived from an attribute score. Exactly which ability modifier you use is determined by what you’re trying to accomplish. Usually a sword swing applies your Strength modifier, whereas remembering the name of the earl’s cousin uses your Intelligence modifier. A magic item might also grant you a bonus to a roll.

When attempting a check that involves something that you have some training in, you will also add dice to your dice pool. This depends on your proficiency rank: untrained, trained, expert, or master. If you’re untrained, then you gain no additional dice and must rely on luck, the raw talent represented by your modifier and any bonuses from the situation. Otherwise, the number of bonus dice that are added to your dice pool depends on your proficiency rank. If you are trained, then this bonus is equal to 1d20 for a base dicepool of 2d20-keep-the-highest-one (2d20kh1). Higher proficiency ranks further increase the number of dice that you add to your pool.

Proficiency Rank	Dice Pool
Untrained	1d20
Trained	2d20kh1
Expert	3d20kh1
Master	4d20kh1

Your dice pool can be futher modified by circumstances, such as when you are hidden or flanking.

Once you have determined the final size of your dice pool and modifiered, roll the dice.