Hey folks, I'm currently working on a small game project with a couple of friends to broaden my understanding of houdini (and houdini engine). Currently I'm trying to set up a very basic character generator. It should output characters that look like minecraft avatars, but with adjustable arm, leg and torso size (just to understand the workflow and go more into Detail from there on).

With the “bones from curve” shelf tool I can already achieve something as intended, but doesn't update if I change the curve it was created with. Is there an option to create a bone chain that updates dynamically, so I can output several already rigged characters?

there isn't any built-in option but you can build something like this fairly easily with expressions or python.
if you have a bone chain that have a bone per curve segment you can set the bone root position to a point and then set it's length to the distance to the next point etc…

if you have a hip file that demonstrates your setup that might help provide some more advice.