Complex sentence: Low fantasy places relatively less emphasis on typical elements associated with fantasy, setting a narrative in real-world environments with only vague elements of the fantastical, sometimes just enough to make ambiguous the boundary between what is real and what is purely psychological or supernatural.
Split into simpler sentences: Low fantasy places relatively less emphasis on typical elements associated with fantasy, setting a narrative in real-world environments with elements of the fantastical. Sometimes just enough fantastical elements to make ambiguous the boundary between what is real and what is purely psychological or supernatural.