Mistborn — Brandon Sanderson

Brandon Sanderson's Mistborn trilogy (2006-2008) and its sequels demonstrate his principle of "hard magic" — fantasy systems with internally consistent rules, limitations, and costs that can be understood and used by the reader to solve problems. The original trilogy's inversion (a world where the Dark Lord won 1,000 years ago) and its extraordinary final act make it one of the most inventive epic fantasies of the 21st century.