Honesty is one of Fallout GURPS disadvantages. See: Fallout GURPS.
You MUST obey the law, and do your best to get others to do so as well. You are compulsive about it; this is essentially another type of Code of Honor. This is a disadvantage, because it will often limit your options! Faced with unreasonable laws, you must roll against IQ to see the need to break them, and against Will to avoid turning yourself in afterward! If you ever behave dishonestly, the GM may penalize you for bad roleplaying. You are allowed to lie if it does not involve breaking the law. Truthfulness is a separate disadvantage.”— Steve Jackson Games GURPS sources
With the abandonment of GURPS, Honesty was removed from the game