Have you ever needed to elude someone, but couldn't because they
knew what you looked like? If so, Disguise may be just what you
are looking for.
Disguise will allow a character to conceal their identity, with varying degrees of success. It is easy to disguise yourself so that you can't be recognized from a faded Polaroid; it is difficult to disguise yourself so that your best friends cannot recognize you.
Disguises will generally have a difficulty of 0 (although the GM may rule otherwise in cases of extreme costumes). There may be modifiers applied.
Sample modifiers to Disguise check:
Since characters tend to know themselves fairly well, it is hard for them to fool themselves. Therefore, the GM rolls all Disguise skill checks. If the result is within 25 of the effective skill level (either way), the character is satisfied with the result. If the check passes by more than 25, the character is pleased with the result. If the check fails by more than 25, the character is not pleased with the result. In the case of critical successes and failures, the character will be very pleased (or displeased) with the result.
After making the roll, the GM will subtract the roll from the character's effective skill level (including difficulty and modifiers), and record this number somewhere. If the skill check succeeds, this number will be positive; if it fails, this number will be negative.
When the disguise comes into play, the character who is being deceived gets an INT check to see through the disguise. The difficulty applied to this INT check will be the number recorded earlier for the disguise. The GM will also assign any modifiers that seem appropriate.
Sample modifiers to INT check:
If the INT check succeeds, then the deceit has failed to some extent. If the check fails, the disguise was successful.
If the disguise is being used in conjunction with some other skill (eg. Con Artist), make the victim's INT check against the Disguise first, and then modify their check against the other skill by the amount the first check passed or failed by.
Dirk has a Disguise skill of 78, and a Con Artist skill of 64. He is going to attempt to con another character, who has an INT of 59.
Dirk plans this caper well in advance, so the GM decides to allow a modifier of 30, to take into account the fact that appropriate materials may be secured. The GM then makes Dirk's Disguise check against a skill of 108(=78+30), and rolls a 42. The difference is 66(=108-42), which is recorded for later reference. 66 is greater than 25, so Dirk is pretty pleased with the results.
Some time later, the con attempt is made. The victim must make an INT check to see through the disguise at -7(=59-66), which is very difficult (the 5% minimum comes into play here). He rolls a 15, which is a failure by 22(=15-(-7)=15+7). When he makes an INT check against the con attempt, there will be a modifier of -22 applied by the GM.