Deceive is the skill about lying to and misdirecting people.
Use Deceive to bluff your way past someone, or to get someone to believe a lie, or to get something out of someone because they believe in one of your lies. For nameless NPCs, this is just an overcome roll, but for PCs or named NPCs, it requires a contest, and the target opposes with Empathy. Winning this contest could justify placing a situation aspect on your target, if buying into your lie could help you in a future scene.
Deceive is the skill you use for determining if a disguise works, whether on yourself or others. You’ll need to have the time and supplies to create the desired effect. (Note: This is mainly a Hearts of Steelthing; in some games, this may not be appropriate for Deceive by default and should require a stunt.)
You can also use Deceive to do small tricks of sleight-of-hand and misdirection.
Create an Advantage:
Use Deceive to create momentary distractions, cover stories, or false impressions. You could feint in a swordfight, putting an opponent Off-Balance and setting you up for an attack. You could do the whole, “What’s that over there!” trick to give you a Head Start when you run away. You could establish a Wealthy Noble Cover Story for when you attend a royal ball. You could trick someone into revealing one of their aspects or other information.
Deceive is an indirect skill that creates a lot of opportunities you can capitalize on, but it doesn’t do direct harm to an individual.
You can use Deceive to throw off Investigation attempts with false information and to defend against efforts made to discern your true motives with the Empathy skill.