D&D 3.5 Forgery, Skill - New Tasks

Players Handbook; SRD Skill Link

Forged Papers: Official documents can provide an excellent means of proving yourself and reinforcing your point. With properly forged documents - created with a normal use of the Forgery skill and opposed by the viewer's Forgery check(or an Intelligence check for those without ranks in Forgery) - you can gain special bonuses to certain skills due to synergy.

At the DM's discretion, you can forge documents that grant a +2 circumstance bonus on specific Bluff, Diplomacy, or Intimidate check. These false credentials become, in effect, the perfect tool for the job and provide a bonus much like the bonuses provided to other skills by masterwork tools. Unlike other bonuses, these apply only when you present the documents and the creature you are interaction with does not detect the forgery. If you present forged documents and they are detected as a forgery, the check you were attempting to use the documents for automatically fails. The DM is also free to rule that there are other repercussions in such situations.