[RPG] list of all player moves in Apocalypse World

History (Hx) is a measure of how well you know someone. Fictionally this might be knowing secrets about them, understanding how they think, knowing their history of violence and being able to predict what they might do, knowing how to work smoothly with them, and/or knowing how to push their buttons or poke their raw emotional wounds and thereby manipulate them. The game doesn't require that you detail this, but you'll probably start with a vague idea anyway.

All together, those kinds of fictional foundations for "how well do I know them?" gives you a certain amount of hold over them, represented mechanically by the Hx rules. When they are trying to do something, you can describe how you help them or interfere with them. If it's fictionally sensible, then you roll+Hx to apply the +1 (for help) or -2 (for hindering) to their roll. The rules recommend rolling at the same time, but it's not strictly necessary.

History changes in three ways. With the end of session move, each player picks a PC who they think knows their character better than before. Usually it will be obvious, but occasionally they'll have to think about it. Either way, once they choose it will probably be obvious how the fiction is related to this change. This won't require any special handling to represent in the fiction.

The other way is the rollover when your character's Hx hits +4 with another PC and has to reset to +1 (while getting to mark experience). The rollover from Hx+4 to Hx+1 can be thought of as a new "level" of understanding of someone. You've had a small epiphany about how they tick, but now you're in slightly uncertain territory with them while you integrate this new understanding. Mechanically, your enhanced knowledge of them turns into marking for improvement (which generally makes you more competent, including when dealing with that PC), and allows you the chance to build up your understanding of them again.

The third way Hx can change is due to a classe's special move triggered by sex, but those are self-explanatory when it comes to the fiction.

There's a discussion on creating custom moves that represent difficulty, first thing in the Advanced Fuckery chapter (p. 268-9). You've got the basic idea already, and your suggestions map right on to some of the ideas. To summarise the ways you can made a move reflect a difficult task:

• You can make a general move that lets you change the difficulty with a -1 or -2 when "things are tough", but most groups find this custom move boring/annoying/not a valuable addition. (This one isn't relevant to you particular case but here for completeness.)

• You can cover difficulty into a more specific, but still general "when the NPC is strong" move, treating it like the NPC is interfering with a 10+, giving the PC's roll a -2. This is a totally legit thing to do as the MC in Apocalypse World and matches one of your ideas. Just give them a -2, because reading Uncle Richard is just that hard.

• You can make a move that just layers itself over another more basic move, modifying its outcome. Something like, "when you're trying to read Uncle Richard it's acting under fire, and the fire is: Uncle Richard is disappointed in you." This can have whatever variations you can think of, and is just like one of your ideas.

• You can roll difficulty right into the substance of a move, saying "when you read Uncle Richard…" and then giving a new, more interesting, tailored, but ultimately fictionally disadvantages list of options on 7-9 and 10+.

  You can mirror an existing move or make it a subset of options, as you suggested above, but to do it cleanly just crib the options and make it a move all to itself without mentioning the basic move. If you want to do it with style, change the options so they reflect the idea that this move doesn't get you want so easy, making the choices tougher, meaner, and more interesting in their focus on this particular person.

All that is to say, you've got the right idea: make a custom move, however you like, to reflect Uncle Richard being damn inscrutable. Either just make it work, or make it cool, but make it.

And of course, you can always just say, "Yeah, ok. But doing that is Acting Under Fire and the fire is Uncle Richard is disappointed in you." That's just fine for ad hoc difficult situations. When you're finding you want to do that every time a particular circumstance comes up, then that's exactly when you should be (as you were) thinking of making a custom move for it.