Create Forgery

Requirements You provide the proper writing materials for your forgery.
You create a forged document, usually over the course of a day or a week. The GM rolls a secret DC 20 {Society} check. If you need to forge a specific person's handwriting, you need a sample of that person's handwriting. Otherwise, you need only to have seen a similar document, and you gain up to a +4 circumstance bonus to the check (the GM determines the bonus).
Success The forgery is of good enough quality that passive observers can't notice the fake (but see Examining Forgeries).

Failure The forgery has some obvious signs of being a fake, potentially allowing passive observers to detect it. Each time a passive observer sees the document, the GM compares your check result to the observer's Perception DC or Society DC, whichever is higher. If your result doesn't exceed a passive observer's DC, that observer knows the document is a forgery.
Examining Forgeries
A creature on the lookout for forgeries, even one who was fooled on a passive glance, can take time to closely examine a document to see if it's a forgery. They apply different techniques and analysis methods to look beyond the surface elements and attempt a secret Perception or Society check against the forger's Society DC; any bonus you had to create the forgery initially applies to this DC. On a success, the examiner knows the document is a forgery. On a failure, they think the document is genuine and can't try again unless they get a new reason to be suspicious of the document. If a PC examines a genuine document, the GM might still pretend to roll a secret check before revealing the document is genuine.