Rules: Skill Use
Making the Rolls
Rolling in general has been covered (number of d6 plus pips, remember one is always a wild die). This is more about skills in play.
Many skills like Bargain and Persuasion can be opposed. Between Players never use social skill rolls (this is role playing game). Against NPCs the DM has the option to skip the rolls, but if they use them instead of rolling against the player give the NPC a set value (4D = 12) and have the player roll against that.
Stealth normally opposes Awareness
Persuasion normally opposes Willpower
Bargain normally opposes Bargain
While a repair roll in an emergency situation can be dramatically appropriate in the case of characters seeking revenue through skill use or trying to build and item it is generally easier to skip the roll. If the pips the character has in the skill match or exceed the difficulty they should be able to do the work. (A character with 4D repair can simply do any repair with a difficulty 12 or less without making a roll).
Equipment modifiers are usually given as set numbers (2, 4, 10) and not broken down into dice. Additionally a character may add 1D to any task by taking twice the normal amount of time. (A character wants to cast a 3rd level spell from a book for the 2 point bonus taking 3 rounds, but isn’t in a hurry so they take 6 rounds and increase the bonus to 1D+2).
Situational modifiers can add up quickly (Character wants to pickpocket the guard with awareness 4D, giving a base difficulty of 12, but the guard is on the look out for trouble adding 2, there are few others in the area also adding 2, and the keycard the character wants is in a breast pocket adding another 4, now the character needs to make a 20 to succeed even though the guard wouldn’t normally get a 20 on a roll; if the same character waited until the area was very crowded dropping difficulty by 4, and the guard was distracted by a screaming child dropping difficulty by 2 they would only need to roll a 10 to get the card from the same pocket).