Types of Roll. 

Advantage & Disadvantage

Sometimes a perk or Chem tells you that you have Advantage or Disadvantage on an ability check, a saving throw, or an attack roll. roll a second D100 or D20, Depending  on the type of roll. Use the higher of the two rolls if you have Advantage, and use the lower roll if you have Disadvantage.

If multiple situations affect a roll and each one grants advantage or imposes disadvantage on it, you don’t roll more than one additional Die. If circumstances cause a roll to have both advantage and disadvantage, you are considered to have neither of them, and you roll one Die. You usually gain advantage or disadvantage through the use of Chems, actions, or perks. Inspiration you can also give a character Advantage on checks related to the character’s personality, ideals, or bonds.
The DM can also decide that circumstances influence a roll in one direction or the other and grant Advantage or impose Disadvantage as a result.

 

CONTESTS

Both participants in a contest make Skill checks appropriate to their efforts. They apply all appropriate bonuses and penalties, but instead of comparing the total to a DC, they compare the totals of their two checks.
The participant with the higher check total wins the contest. That character or monster either succeeds at the action or prevents the other one from succeeding. If the contest results in a tie, the situation remains the same as it was before the contest.

 

PASSIVE CHECKS

A passive check is a special kind of ability check that doesn’t involve any die rolls. representing the average result for a task done repeatedly, or can be used when the DM wants to secretly determine whether the characters succeed at something without rolling dice,
50 + all modifiers that normally apply to the check
For advantage on the check, +25. For disadvantage, -25.

 

WORKING TOGETHER

Sometimes two or more characters team up to attempt a task. The character with the highest skill score  can make an ability check with advantage, help provided by the other characters. In combat requires the Help action
A character can only provide help if
•The task is one that he or she could attempt alone.
•Two or more individuals working together would actually be productive.

 

GROUP CHECK'S

To make a group ability check, everyone in the group makes the ability check. If at least half the group succeeds, the whole group succeeds. Otherwise, the group fails.