EDIT: This first question has been answered, please skip to the "Try again" Question.
the rules say
"You can help someone achieve success on a skill check by making the same kind of skill check in a cooperative effort. If you roll a 10 or higher on your check, the character you're helping gets a +2 bonus on his or her check."
and I've always taken that literally If you roll a 10 or higher on your die then you succeed. I've never allowed players to add their bonuses. but recently I've seen another GM allow players to use their bonuses.
Example: in a tavern, trying to intimidate some thug who is alone as a group. the first person rolls intimidate, they get their bonus to the roll, let's say 10+6, the DC is 20 to intimidate the information out of him. the other four players roll to assist, they get in order 9, 10, 5, and 6.
I've always played it so only the guy who rolled the 10 can assist, so the party in this situation has failed to intimidate.
But, let's say the person who rolled a 9 has a +6 intimidate, Should I add that onto her Aid Another roll? Then the party has two people aiding and thusly they win their intimidate check.
EDIT: This is the "Try Again" question
Furthermore it says in the rules under the "Try again" section
Try Again: You can attempt to Intimidate an opponent again, but each additional check increases the DC by +5. This increase resets after 1 hour has passed.
So if the first player tries to intimidate and fails, she can try again but the DC is increased to 25 from 20. If the whole party failed to Aid do they also have to get that higher DC? Or can a person who tried to Aid and failed make an intimidate check at DC 20? Or if a player wasn't in the room during the first intimidate check can she then come in and try it at the original DC of 20? or if 1 single person fails does that NPC get a +5 for the next hour for everyone encountered?
So really there are tons of questions here. but most importantly is do you get your skill bonus on your aid another checks?
Thanks much for reading all this! :)