The laws of physics of a system provide the underlying structural lattice on which everything else in the system coheres.

Only things that can cohere with that lattice, or with the emergent aggregations on top of it (that is, that coheres indirectly) can stick.

Everything else bounces off, free energy not precipitated out of the solution.

A new law of physics will attract and stick different bits of free energy into structures unlike the other lattice.

It will draw on inputs and energy that didn't "stick" in the previous lattice.

That free energy that can't be put to good use in the old system will be invisible to people in the old system.

To people who are only familiar with the old lattice, the new one will look like it's creating energy out of nothing.