A Little Help from my Friends
This rule is intended to address what I perceive as flaws in the Aid Another (PHB 287) rules.
Firstly, the DC or AC to aid another is no longer 10 but the actual task’s DC-5. In short, it will still be easier for an untrained character to help with a task than for the trained character to actually succeed on his or her own, but, at the same time, untrained characters lacking the relevant abilities will be unable to help with truly esoteric tasks.
Secondly, a failure to meet the aid another DC for a skill check by five or more will result in a penalty of -2 to the helped character’s check. Characters should be reticent to solicit the help of truly rude/clumsy/foolish characters in delicate or dangerous situations. This particular modification applies to skill checks only.
Example: The Mouth tries to diplomatically convince a notoriously formal major-domo into letting the party meet his master despite the advanced hour. The Mouth has +10 and the DC is 25, so he solicits some help. The Guardian, Healer and Seeker choose to help while the Fey tries to catch a passing butterfly. The helpers roll 15, 10 and 5 respectively. The DC to help is 15 (25-10). The Guardian helps the Mouth, granting the standard +2, the Healer’s input is meaningless and the Seeker, with his inquiry about the presence of “hot bitches” within, imposes a penalty of -2.