My players have been disguising themselves a lot, and I thought I'd share the rules we've been using. Basically the player choses a career card he or she wishes to mimic. The test is against fellowship, and the difficulty is dependent upon how different the chosen careers traits are from the players actual traits, starting at easy for no difference (eg ratcatcher to dockhand). Extra difficulty die can be added for different races (lots in some cases), tier differences etc. Fortune/misfortune die can be added for such things as appropriate props, background (eg family connection - get that background written up soonest!) etc., as the GM wishes.
Testing is on a daily basis until the false character is established, then in exceptional circumstances only after that (eg disguised as a watchman and trying to enter a watch-house). Guile can be used to add a trained dice.
One of my characters has also been using a home made talent card 'Master of disguise' - this gives an extra trained dice, and an extra fortune dice (if equipped with a disguise kit).
