When playing NPCs who are hiding something, how much should I reveal (mechanics-wise)?

Question

I have a NPC who's hiding something.

• She has an aspect that she's trying to hide.
• She has the stunt I've Read About That!, which allows her to spend a fate point to use Lore (her cap skill) in place of any other skill for one roll.
• She has the aspect I Planned For This, which makes her a person who's good at planning, which could probably explain her being better at something than she would be if she didn't have the chance to plan.

Now let's say that a player is trying to use Empathy on her to reveal her lies, she's defending with Deceive. I have a series of questions (that are essentially yes/no questions, but please feel free to elaborate) about what the players should know.

1. Should I reveal that I roll to defend for her? (The alternative being using pre-rolled dice scores, I imagine.)
2. If so, should I reveal the result of her dice roll? (Or should I roll out of their sight?)
3. Should the players always know the outcome or not? (Perhaps, if they fail, she covers herself with another lie instead, in addition to any other consequences.)
4. If so, should the players know their shifts (in other words, her exact score) on the ladder (skill + dice) when she's defending? (Or just the outcome?)
5. Should I reveal that she's spending a fate point for a stunt to improve her Deceive Defense roll? (Or do I privately keep track of the NPCs' fate in the current scene?)
6. If so, should I reveal which stunt she's using? (Or just say that she's better than she looks at hiding her motives, implying the use of an unspecified stunt?)
7. Should I reveal that she's spending a fate point to invoke one of her aspects to improve her roll?
8. If so, should I reveal which aspect she's invoking? (Effectively making it permanently known to the players now?)

Answer 1

Fate says that you keep everything out in the open. Even that hidden aspect itself. Players are expected to keep their knowledge apart from their characters and play as such.

If a character takes a shot at discovering the truth, then it's a contest like "empathy vs. deceive" like you described. Per the principles of Fate, every game mechanic should be out in the open as usual, including but not limited to rolls, results, fate point expenditure, aspect and stunt invocations etc. It's the result that makes the difference.

Success means the character gets the upper hand, just like the player expected. Failure however, is the interesting part. Since in a contest, one side's failure is the other one's success, you can set the roll with opposed goals, like the PC trying to create an aspect like "I know what you did last summer", and the NPC trying to even deepen the deception by creating another aspect like "The sweet taste of false hope".

Aspects in Fate are a more versatile tool than you'd expect at first sight. Don't forget that every aspect is a piece of the truth about yur game world. Even when they don't provide game-mechanical bonuses, they still impose themselves on the story. If there is an aspect that implies that it's not public knowledge, something like "Accountant by day, axe murderer by night", it means that most people, including the PC's don't know about it unless some other aspect says otherwise.

Don't get me wrong, the players can and should know about all aspects in play. It's their character who doesn't know. If a player makes his character act as if they know, feel free to ask them how?. If they cannot find or create an aspect that justifies their knowledge, then you can safely say that they do not know it yet, so can't act on it now.

Fate is a different system than most of the classic games we have played. It offers loads of fun if you embrace the thinking behind it and play along :)