CORE RULES DEFINITIONS AND CONCEPTS
This page contains various rules terms that are referred to elsewhere in this rulebook, and gives an overview of some key concepts that form the basis of the rules in general.
MISSIONS
To play a game of Warhammer 40,000, you must first select a mission. The mission will tell you how to muster your armies, create your battlefield and deploy your armies. It will also tell you any special rules that apply to the battle, and (most importantly!) what you need to do to win. You can find out more about missions on the "Missions" page of this site.
ARMY
Each player in a game of Warhammer 40,000 commands an army of Citadel miniatures, hereafter referred to as ‘models’. The mission you have selected will guide you as to how big your army should be.
A good measure of the size of an army is its Power Level – this is determined by adding up the Power Rating of every unit in your army. A unit’s Power Rating can be found on its datasheet.
Warhammer 40,000 is designed to be played with armies of a certain size. If the combined Power Rating of all the models you and your opponent want to use in a battle is less than 15 or greater than 300, then you may find that Kill Team or Apocalypse, respectively, better suits the scale of the game. You can find out more about these games on warhammer-community.com.
- ARMY: Collection of models under your command.
DATASHEETS
The rules that you will need to use the models in your army in a game are presented on datasheets. Each unit has a datasheet; you will need the datasheets for all the units in your army. You can find out more about datasheets one the "Datasheets" page.
KEYWORDS
All datasheets have a list of keywords, separated into Faction keywords and other keywords. The former can be used as a guide to help decide which models to include in your army, but otherwise both sets of keywords are functionally the same. In either case, keywords appear in KEYWORD BOLD in the rules. Keywords are sometimes linked to (or ‘tagged’ by) a rule. For example, a rule might say that it applies to ‘INFANTRY units’. This means it only applies to units that have the INFANTRY keyword on their datasheet. The pluralisation (or not) of keywords does not affect which units the rule in question applies to.
Some datasheets have keywords that are presented in angular brackets, such as <CHAPTER>, <LEGION> and <MARK OF CHAOS>. This is shorthand for keywords that you can select yourself (with certain restrictions, as described in the publication that contains that datasheet). You must decide what these keywords will be at the moment such a unit is added to your army (whether before the battle or during). If another rule uses keywords in angular brackets, then that keyword matches the keyword that you selected of the unit using that rule.
Some units can include models that have different keywords. While a unit has models with different keywords, it is considered to have all the keywords of all of its models, and so is affected by any rule that applies to units with any of those keywords. If a rule only applies to models with a specific keyword, then it instead only applies to models in such a unit that have the correct keyword.
- Keywords: Appear in rules in Keyword Bold font
- Keyworded rules apply to units and models with that keyword.
- <Keywords> are chosen by you when a unit is added to your army.
UNITS
Models move and fight in units. A unit can have one or more models chosen from a single datasheet. All units in the same army are friendly units, and all models in the same army are friendly models. All units in your opponent’s army are enemy units, and all models in your opponent’s army are enemy models. If a rule affects ‘units’ or ‘models’ without specifying that they are friendly or enemy, then it affects either ‘all units’ or ‘all models’, regardless of whose army they are in.
- Unit: A group of models from the same datasheet.
- Friendly models = all models in the same army.
- Enemy models = all models in your opponent’s army.
- Friendly units = all units in the same army.
- Enemy units = all units in opponent’s army.
UNIT COHERENCY
A unit that has more than one model must be set up and finish any sort of move as a single group, with all models within 2" horizontally and 5" vertically of at least one other model from their unit. While a unit has six or more models, all models must instead be within 2" horizontally and 5" vertically of at least two other models from their unit. This is called unit coherency. If a unit cannot end any kind of move in unit coherency, that move cannot be made. Units are primarily moved in the Movement phase, but they can also be moved in the Charge phase and the Fight phase.
Some rules allow you to add models to a unit during the battle; such models must always be set up in unit coherency with the unit they are being added to. Sometimes there will be insufficient room to set up all the models from a unit, or it will not be possible to set up all the models so that they are in unit coherency. When this is the case, any models that cannot be set up are considered to have been destroyed.
- Unit Coherency: 2" horizontally + 5" vertically.
- Each model must be in unit coherency with one other model from own unit.
- While unit has 6+ models, each model must be in unit coherency with 2 other models from own unit.
ENGAGEMENT RANGE
Engagement Range represents the zone of threat that models present to their enemies. While a model is within 1" horizontally and 5" vertically of an enemy model, those models are within Engagement Range of each other. While two enemy models are within Engagement Range of each other, those models’ units are also within Engagement Range of each other. Models cannot be set up within Engagement Range of enemy models.
- Engagement Range: 1" horizontally + 5" vertically.
- Models cannot be set up within Engagement Range of enemy models.
BATTLEFIELD
All battles of Warhammer 40,000 are fought upon rectangular battlefields. This can be any surface upon which the models can stand – a dining table, for example, or the floor. Your mission will guide you as to the size of battlefield required, but it will be commensurate with the size of the armies you are using. Battlefields will be populated with terrain features.
TERRAIN FEATURES
The scenery on a battlefield can be represented by models from the Warhammer 40,000 range. These models are called terrain features to differentiate them from the models that make up an army. Terrain features are set up on the battlefield before the battle begins. You can find out more about terrain features in the Warhammer 40000 Core Rulebook.
Unless the mission you are playing instructs you otherwise, you should feel free to create an exciting battlefield using any terrain features from your collection that you wish. In general, we recommend having one feature on the battlefield for every 12" by 12" area (rounding up). Don’t worry if your battlefield doesn’t match these requirements, but keep in mind that playing on a battlefield that is either a barren wasteland or filled to overflowing with terrain features may give an advantage to one side or the other.
MEASURING DISTANCES
Distances are measured in inches (") between the closest points of the bases of the models you’re measuring to and from. If a model does not have a base, such as is the case with many vehicles, measure to the closest point of any part of that model; this is called measuring to the model’s hull. You can measure distances whenever you wish.
If a rule refers to the closest unit or model, and two or more are equidistant, then the player who is controlling the unit that is using the rule in question selects which unit is the closest for the purposes of resolving that rule.
- Distances measured in inches (").
- Always measure closest distance between bases (or hulls).
- Hull = Any part of a model that does not have a base.
- Can measure distances whenever you want.
- If several units tied for closest, player resolving the rule selects which is closest.
WITHIN AND WHOLLY WITHIN
If a rule says it applies ‘within’ a certain distance, it applies at any distance that is not more than the specified distance. For example, within 1" means any distance that is not more than 1" away.
If a rule says it affects models that are ‘within’, then it applies so long as any part of the model’s base (or hull) is within the specified distance. If a rule says it affects models that are ‘wholly within’ then it only applies if every part of the model’s base (or hull) is within the specified distance.
If a rule says it affects units that are ‘within’, then it applies so long as any part of any model’s base (or hull) in that unit is within the specified distance. If a rule says it affects units if ‘every model in that unit is within’ then that rule applies so long as any part of every model’s base (or hull) is within the specified distance. If a rule says it affects units that are ‘wholly within’ then it only applies if every part of every model’s base (or hull) in that unit is within the specified distance.
- Model within = any part of model’s base (or hull).
- Model wholly within = every part of model’s base (or hull).
- Unit within = any model within.
- Unit wholly within = every model wholly within.
DICE
In order to fight a battle, you will require some six-sided dice (often abbreviated to D6). Some rules refer to 2D6, 3D6 and so on – in such cases, roll that many D6s and add the dice results together. If a rule requires you to roll a D3, roll a D6 and halve the value shown on the dice to get the dice result (rounding fractions up). If a rule requires a D6 roll of, for example, 3 or more, this is often abbreviated to 3+.
All modifiers (if any) to a dice roll are cumulative; you must apply all division modifiers before applying all multiplication modifiers, and before applying all addition and then all subtraction modifiers. Round any fractions up after applying all modifiers. A dice roll can be modified above its maximum possible value (for example, a D6 roll can be modified above 6) but it can never be modified below 1. If, after all modifiers have been applied, a dice roll would be less than 1, count that result as a 1.
- D6 = A six-sided dice.
- D3 = D6 divided by 2 (rounding up).
- All modifiers cumulative.
- Apply modifiers in the following order: division, multiplication, addition, then subtraction.
- Round fractions up after all modifiers have been applied.
- Dice roll cannot be modified to less than 1.
RE-ROLLS
Some rules allow you to re-roll a dice roll, which means you get to roll some or all of the dice again. If a rule allows you to re-roll a dice roll that was made by adding several dice together (2D6, 3D6 etc.) then, unless otherwise stated, you must re-roll all of those dice again. If a rule allows you to re-roll specific dice results, only those dice can be re-rolled. If a rule allows you to re-roll a specific dice result, but the result is obtained by halving a D6 (such as when rolling a D3), you use the value of the halved roll to determine if it can be re-rolled, not the value of the original D6. For example, if a rule states to re-roll results of 1, and you roll a D3, you would re-roll if the D6 rolled a 1 or a 2 (which is then halved to get a D3 value of a 1).
You can never re-roll a dice more than once, and re-rolls happen before modifiers (if any) are applied. Rules that refer to the value of an ‘unmodified’ dice roll are referring to the dice result after any re-rolls, but before any modifiers are applied.
- Re-roll: Roll dice again.
- Re-rolls are applied before modifiers (if any).
- A dice can never be re-rolled more than once.
- Unmodified dice: Result of roll after re-rolls, but before modifiers (if any).
ROLL-OFFS
Some rules instruct players to roll off. To do so, both players roll one D6, and whoever scores highest wins the roll-off. If there is a tie for the highest roll, make the roll-off again. Neither player is allowed to re-roll or modify any of the D6 when making a roll-off.
- Roll-off: Both players roll a D6 – highest wins.
- Roll again if a tie.
SEQUENCING
While playing Warhammer 40,000, you’ll occasionally find that two or more rules are to be resolved at the same time – e.g. ‘at the start of the battle round’ or ‘at the end of the Fight phase’. When this happens during the battle, the player whose turn it is chooses the order. If these things occur before or after the battle, or at the start or end of a battle round, the players roll off and the winner decides in what order the rules are resolved.
- If several rules must be resolved at the same time, the player whose turn it is chooses the order to resolve them.
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