Hindsight Experience Replay, how to define a partially-known End-Goal
I've got an answer from the Author:


  The simplest solution would be to have 2 types of goals - a) specific hp and position; and b) specific hp, arbitrary position. I haven't tried anything like that though.


Based on the response I reason it might work if we do the following:
use a placeholder value, perhaps for the last component of the input vector.
This way the DQN will notice that when this "last bit" is on, only health matters.

&lt;hp,  x1,x2,x3,  q1,q2,q3,  chestID, handsID, headID, feetID,   placeholder0or1&gt;


Edit: if you know a better way, please share it as an answer!