Balancing game design to fit your precise adventuring group is a heroic task. Every party of player characters is different - in number, in levels, in gear, in support. And you, as game master, have your own preferences - whether losing the whole party is not a hard loss sometimes, or if every painstakingly built character is irreplaceable. Bereft of an easy way to answer to questions about whether or how a new piece of content fits the party, Game Masters are forced to hope for the best and rely on a handful of rules-of-thumb to reestablish control when play goes off the rails.
Advanced Statistics for Roleplaying is a book meant to allow you to ask and answer those questions. Hopefully, you will find in here processes that turn the numbers of game play (dice, targets, enemies) into meaningful measurements. More than merely helping you crunch challenge ratings, this book should provide you with random encounters that really are just for fun, meaningful adversaries that your players can eventually rise up to, and ways to take your hard-written plots off the rails, risking critical plot points behind a random die roll, yet still be confident that your carefully crafted story will not be