I've mentioned before that there's some additional introductory materials in Core Rules, so that seems like a reasonable place to start the discussion!
Here's the content of three pages of the introduction, where I discuss the following:
- Which books are required to play the game, and who needs copies of them. Also why the game is split into separate books in this way, and the benefits of this approach. (Naturally, this section will appear in a modified form in the all-in-one hardcover.)
- Which other games Old-School Essentials is compatible with. I think this is a super important point, as the sheer amount of material that all works together is far from obvious to a newcomer to the old-school scene.
- The basic assumptions of the game, around which the rules are forged.
Required BooksOld-School Essentials is split into a set of books, known as rules modules, allowing the game to be tailored to different settings, genres, and styles of play.
Core Rules (This Book)Contains the core rules of the game that are common to all settings, genres, and styles of play. All players need access to a copy of this book. Each player may want their own copy, or a group may share one or more copies among themselves.
Genre RulesContains the game rules specific to a setting or genre of fiction in which the games take place. A genre rules book typically describes the classes of adventurers that can be played, and provides lists of weapons, armour, vehicles, services, and strongholds that may be purchased. All players need access to a copy of the genre rules book that the group is using.
SpellsLists the spells that can be cast by character classes in the corresponding genre rules book. Only players who are playing a character capable of casting spells need access to a copy of the spells book.
MonstersLists adversaries and monstrosities that may be encountered during adventures in a particular setting or genre. Only the referee needs access to a book of monsters.
TreasuresLists wondrous and precious items that may be found during adventures in a particular setting or genre. Only the referee needs access to a book of treasures.
Mix and MatchWith the rules of the game split up into separate modules, it is easy to swap out individual elements, replacing them with alternatives. In this way, different settings and genres may be combined. For example, a group may wish to use a classic fantasy genre rules book along with a book of alien technology treasures, lending a science-fantasy feel to the game.
Multiple rules modules of the same type may also be used together. For example, a book of classic fantasy monsters might be augmented with a book of lost world monsters, for a campaign set around a dinosaur-infested jungle that time forgot.
As the core rules do not assume the use of any specific rules modules of the other types, all may be combined freely.
Roll Your OwnIn addition to using the rules modules published in The Old-School Essentials product line, groups may wish to create their own rules modules, tailoring the game to their own needs.
CompatibilityThe old-school gaming scene is sitting on a secret: a huge number of games, despite having different brand names on their covers, are highly compatible! This cross-compatibility between many games means that a great wealth of adventures, campaign settings, and rules supplements can be used with Old-School Essentials.
The Basic / Expert RulesOld-School Essentials is 100% compatible with the 1981 edition of the world’s most popular fantasy RPG, commonly known as the Basic / Expert edition (B/X for short). Any material published for the Basic / Expert rules can be used directly with Old-School Essentials. Decades of adventure are at your fingertips!
Other Basic / Expert GamesOver the last decade, a large number of old-school adventure games have been published, many of which—like Old-School Essentials—are also closely compatible with the Basic / Expert rules. Some of the most popular are Labyrinth Lord (by Daniel Proctor), Lamentations of the Flame Princess (by James Edward Raggi IV), and Basic Fantasy RPG (by Chris Gonnerman).
While each of the games mentioned above adds its own twists to the Basic / Expert rules, they are highly compatible, making it easy to use material published for these games with Old-School Essentials.
Other EditionsAdditionally, material published for all 20th century editions of the world’s most popular fantasy RPG (for example, the classic Advanced edition from the 1970s) is also largely compatible with Old-School Essentials.
The rules of other editions do differ somewhat from the Basic / Expert rules, so some amount of adaptation work may be required in order to use these materials with Old-School Essentials. This is not recommended for beginning players, but for those who are familiar with the rules, such adaptation is not complicated.
Adaptation GuidelinesConcrete guidelines are beyond the scope of this introduction. However, a guide to adapting other, similar rules sets for use with this one is available as a free download from necroticgnome.com for those who want more information on this topic.
Adventure GamingThe rules in this book provide a solid and flexible basis for running adventure games in many different fantastic settings. The following elements are fundamental.
Peril and AdventurePlayers take on the role of people who are drawn to confront danger, in search of wealth, ancient secrets, and wonder. These bold individuals are known as adventurers, and are the focus of the game.
The danger and reward of adventure is most commonly found in two types of locations: wilderness and dungeons.