The focus of Assertion-Based Design, Second Edition is three-fold: -How to specify assertions, -How to create and adopt a methodology that supports assertion-based design (predominately for RTL design), -What to do with the assertions and methodology once you have them. To support these three over-arching goals, we showcase multiple forms of assertion specifications: Accellera Open Verification Library (OVL), Accellera Property Specification Language (PSL), and Accellera System Verilog. The recommendations and claims we make in this book are based on our combined actual experiences in applying an assertion-based methodology to real design and verification as well as our work in developing industry assertion standards. Differences between the first edition and the second edition include: -Updates to the manuscript based on newer versions of standards, -Corrections to errata identified during reviewer feedback, -New material that presents techniques on how to avoid common ambiguity errors, -New material that discusses high-level requirements modeling for specification.