A mysterious book

On his front porch sat a small leatherbound tome. The word RULES was burnt into the cover.

Picking it up, John peered around. No mysterious old men or mischievous gods - not even a note from his grandpa explaining that it was a family heirloom. John shrugged and closed the door.

The first page of the book had a few lines written in archaic script.

To thee whomst e'er this book shall find,
The laws of earth thy hand shall bind.

Ignoring the mangled scansion, forced rhyme and hideous grammar, John pondered the poem. He immediately reached the obvious conclusion that the book allowed him to change the laws of the universe with stroke of a pen.