I am just paraphrasing the book, but it is important that a hard move be irrevocable. It involves consequences that cannot be walked back, or reversed, or dealt with just before they actually happen. 'A mutant cannibal suddenly leaps out from the shadows and swings her machete at you!' is not a hard move; 'A mutant cannibal leaps out from the shadows and cuts off your hand with a machete!' is.
While hard moves do produce 'open-ended story elements', that is not really their motivating force, or an important consideration when making them. Hard moves close down possibilities as well as open up new ones, precisely because they are real consequences that have happened already.
Now obviously not all hard moves are brutal or bloody, but they do I think all share the characteristic that the hand-machete example illustrates. A thing has happened, and now the PCs can react.
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But I feel like this is all covered (in much more detail) in the book. I'm not convinced that thinking about the numbered list is going to help -- more likely it is going to make the MC hesitate, or soften the move, or make the move in accordance with something other than the Agenda and Principles that are meant to guide the game. I mean, what is the intersection between 'make the PCs lives interesting' and 'create as much excitement and player involvement as possible' -- do you need to think about the second one specifically, or will doing the first naturally produce the second?
I'm not sure you should be worrying about your players' specific desires, when making a hard move. The hard move is your turn to talk, after all; it's about what you think should happen, what seems interesting and exciting to you. It's about the PCs, sure, but it's not about guessing what the players want -- the PCs are the way you know what the players want.
Similarly, what is the interaction between 'make Apocalypse World seem real' and 'create as many new open-ended story elements as possible'? What if the realistic result/move is destructive to 'story elements' (if that's a possible thing for them to be?)? Aren't you 'looking through crosshairs' anyways?
I mean, there is a long list of specific hard moves, and also a list of specific Agendas and Principles; is there a benefit to trying to generalize some sort of set of meta-principles about hard moves? Or is it better to think about some specific MC move that you rarely use, or have trouble using effectively?