[dotsam]

> Certain interpretations (e.g., the "Many Worlds" interpretation of QM) are more conducive to this possibility than others.

> Generally, "free will" is simply stated as "the freedom to do otherwise".

In the Many Worlds interpretation, as I understand it, everything that can happen, does happen (as it would in a single universe of infinite extent). So no matter what you choose to do in one universe, the multiverse-wide outcome is predetermined: copies of you always make all choices not forbidden by the laws of physics.

I think this just pushes the problem of determinism out to the multiverse as a whole.