Core Concepts

Before you move a single model, a handful of foundational ideas underpin every game of Warhammer 40,000: how armies and units are defined, who counts as the active player, how you measure and roll, and how a unit's nerve is tested with Leadership and Battle-shock rolls.

Armies, units and models

Each player fields an army built from units, and every unit gathers one or more models. You are the controlling player of everything in your own army, so whenever a rule mentions the "controlling player," read it as whoever commands the models that rule is affecting.

The models in a unit act as one body, moving and fighting together. Most sit on a base, and that base is treated as part of the model for all rules. Any ability or effect that lands on a unit reaches each of its models.

Rules frequently distinguish friend from foe:

If a rule simply refers to units or models without saying "friendly" or "enemy," it affects any unit or model regardless of which army it belongs to.

Active player and opposing player

At any given moment one player is the active player and the other is the opposing player. Which is which shifts constantly through the battle, but every player is always one or the other. The instant one player becomes active, the other becomes the opposing player.

While it is nobody's turn — for example at the very start or end of a battle round — the active player is whichever player takes the first turn of that battle round. During a player's own turn that player is usually active, though two situations briefly pass active status across the table:

This matters because it determines who resolves reactive rules during an opponent's turn.

Measuring distances

All distances are measured in inches ("), and you may measure at any time you like — there is no restriction on checking a range before committing to an action. Unless a rule states otherwise, when you gauge where a model stands in relation to anything else on the table, you measure to or from the nearest point of that model's base.

Dice

The game uses six-sided dice, abbreviated to D6. You will see dice rolls written several ways:

Leadership rolls

For a unit's Leadership roll, its controller rolls 2D6. Should the total reach or beat at least one of the Leadership (Ld) values carried by the unit's models, the roll passes; if it falls short, it fails. Whatever rule instructed you to make the roll spells out what success or failure means.

Battle-shock rolls

A Battle-shock roll is simply a Leadership roll made for a specific reason, most often during the Command phase. If the roll succeeds, nothing happens. If it fails, the unit — and every model in it — becomes battle-shocked.

While a unit is battle-shocked:

Battle-shock represents a unit's discipline buckling under casualties or disruption, and shaking it off usually has to wait until a later turn.

Frequently asked questions

What is the difference between the active player and the opposing player in Warhammer 40,000?

At any moment one player is the active player and the other is the opposing player, and which is which shifts constantly through the battle. Whoever moves, shoots or fights with a unit becomes the active player for the duration of that action, which decides who resolves reactive rules.

How do you measure distances in Warhammer 40,000?

All distances are measured in inches ("), and you may measure whenever you like with no restriction on checking a range first. Unless a rule says otherwise, you measure to or from the nearest point of a model's base.

What does D3 mean in 40k dice rolls?

D3 means you roll a single D6 and halve the result, rounding up, so a 1 or 2 gives 1, a 3 or 4 gives 2, and a 5 or 6 gives 3. Notations like 2D6 mean roll that many dice and add them together, while a modifier such as D6+1 adds the fixed value to the total.

How does a Battle-shock roll work in Warhammer 40,000?

A Battle-shock roll is a Leadership roll made for a specific reason, most often during the Command phase, where the controller rolls 2D6 against the unit's Ld. If it fails, the unit becomes battle-shocked; if it succeeds, nothing happens.

What happens when a unit is battle-shocked in 40k?

While battle-shocked, a unit's models have their Objective Control (OC) treated as "-" so it cannot hold objectives, its controller cannot target it with Stratagems, and it cannot start or complete an action. This represents its discipline buckling under casualties or disruption.