System Reference Document 5.1
System Reference Document 5.1 © 2016, Wizards of the Coast, Inc.; Authors Mike Mearls, Jeremy Crawford, Chris Perkins, Rodney Thompson, Peter Lee, James Wyatt, Robert J. Schwalb, Bruce R. Cordell, Chris Sims, Steve Townshend, based on original material by E. Gary Gygax and Dave Arneson.