Editing Scratch:Basic Rules (section)

===Rolls===
 
Some actions, like a character attacking another character, have a chance of success and a chance of failure. To determine whether the action succeeds, roll a twenty-sided die. (If you do not have a twenty-sided die, see "[[Scratch:Twenty-Sided Die Alternatives|Twenty-Sided Die Alternatives]]" below.) Modifiers, such as ability levels, are then added to certain types of rolls. If the total is greater than or equal to the difficulty of the action, then the action succeeds. If the die roll is 20 before adding an ability level or other modifiers, then the action is ''automatically successful''.  If the die roll is not 20 and the total is less than the difficulty, the action fails.

Rolls may allow a character to use specific ability levels as a modifier. "Make a command roll (difficulty 25)" or "beat a command roll of 25" means a player can roll a twenty-sided die. If he has at least one level of command ability, then he can add his command ability level to the roll. The character is only successful if the total is equal to or greater than 25, or the player rolls a 20 before adding his character's command ability. As another example, suppose a character with 3 levels of craftsmanship ability has to make a craftsmanship roll of 15. He rolls 12, and 12 plus 3 is equal to the difficulty 15, so he is barely successful.

Some rolls require specific abilities. "Make a healing roll (difficulty 11, requires healing ability)" or "Make a healing roll of 11 (requires healing)" means a character can only attempt the action if they have at least one level of healing ability. If they do have at least one level of healing ability, they can add their healing ability to a twenty-sided die roll, and the action is successful if the roll is 11 or greater.