The Principles of Combat are the basic Rules of the game, and will explain how to undertake all basic and advanced game actions - such as attacking or moving.This section contains all of the Rules that govern resolving actions in a Battle, from moving and attacking, to Tactical Statuses and Reactions. The section that follows, The Rules of Battle on page 239, covers when these actions are resolved and in what order - as well as detailing any unique Rules that occur in the Phases of a Turn.
This section is broken down into two discrete parts: Basic Principles and Advanced Principles. Basic Principles covers making attacks and moving Models, as well as the Model Characteristics and Model Types required to resolve such actions. Advanced Principles covers Tactical Statuses, Reactions, Psychic Powers and more advanced Rules for Models that use the Vehicle Type, and Models that use the Flyer Sub-Type.
Rules and Special Rules
The term Rule refers to any instructions that allow Players to resolve game actions as part of a Battle, covering all of the interactions between Models and Units (such as moving, Shooting and making Assaults). All of the material in the Principles of Combat, Rules of Battle and Battles in the Age of Darkness sections of this book are considered to be Rules. Special Rules modify how a Rule works, but do not present new basic game instructions, and in this book are mostly found in the Armoury of the Age of Darkness section. In all cases, Special Rules take precedence over Rules where the two present differing instructions.
Core And Expanded
In various places in this book, Players will find the term Core used to describe Rules and Special Rules. The term Core is used to refer to anything found in this rulebook, the Core Rulebook which presents all of the Rules and Special Rules that form the foundation of the Horus Heresy: Age of Darkness game. Any Rules or Special Rules presented in other Horus Heresy books, downloads or other publications are not Core Rules. This allows us to differentiate between the baseline Rules and a game making use of a larger body of newer and more expansive Rules when necessary.
The term Expanded is not used in this book, but refers to Rules or Special Rules that are considered optional and not part of the base game. Usually this will be because such Expanded Rules are more complex or less balanced than other Rules or Special Rules, and by use of the label make it plain to Players when they are making use of such Rules. This does not mean that Expanded Rules are not ‘proper’ Rules, but merely serves to highlight for Players when they are using something outside of the pale of the Core Rules. Note that if a Rule or Special Rule is not Core it is not automatically Expanded, a Rule or Special Rule that is an Expanded Rule will specifically state such.