Terrain

Terrain features shape every game of Warhammer 40,000, dictating where models can move and what they can see. This page explains how terrain is placed, the categories it falls into, and the visibility rules — Benefit of Cover, Hidden, Obscuring and Solid — that decide who can shoot whom.

Placing terrain

Before the battle begins, both players furnish the table with terrain features. You can do this in three ways: mark out a defined boundary (a base, tile or mat) and set one or more features wholly inside it; drop a single feature directly onto the table; or arrange two or more features so that together they mark out the edge of an area. Whichever method you use, the patch of battlefield inside that boundary — or covered by that feature — is a terrain area. A mission's deployment map may fix where each terrain area sits and how large it is; if it does not, agree the boundaries with your opponent before the first turn.

Terrain categories

Every terrain feature belongs to one of three categories, and that category governs how it affects movement and sight lines. Note that features sharing a single terrain area can be different categories.

• Exposed offers almost no protection and never slows a model. Craters, razorwire and scattered debris are typical examples.
• Light can grant cover against incoming fire but does nothing to hinder movement or provide lasting shelter. Think barricades, low walls and statuary.
• Dense blocks even the largest war machines and can conceal whole units from view. Buildings, ruins, armoured containers and woods are dense features.

A deployment map may specify which categories should appear in each terrain area; meeting those requirements gives the most balanced game.

Terrain and movement

Any model can move both horizontally and vertically through Exposed and Light features without penalty. Dense features are more restrictive:

• INFANTRY, BEASTS, SWARM and MOBILE models move horizontally through Dense terrain freely.
• INFANTRY, BEASTS and SWARM models may also move vertically through Dense terrain.
• Any other model can only pass horizontally through Dense terrain where every section its base would cross is 2" or less in height. Where a section is taller, the model must climb it vertically instead. Such models cannot pass through ceilings or floors, and cannot finish a move on any surface above ground level.

Moving vertically to climb up or down a feature carries two conditions: the model must stay within ½" horizontally of that feature, and both the vertical distance up and the vertical distance down are added to the total distance the model's unit has moved this phase.

Models may be set up or finish a move on the ground level of any feature. They can also end above ground level only if the model has the INFANTRY, BEASTS, SWARM, FLY or MONSTER keyword, and after the move it sits stable with no part of its base overhanging the outer edge of that surface.

Terrain and visibility

Four rules determine whether terrain hides a target: Benefit of Cover, Hidden, Obscuring and Solid.

Benefit of Cover

When a ranged attack targets a unit, that unit has the benefit of cover only if every model in it satisfies at least one condition: the model is an INFANTRY, BEASTS or SWARM model standing within a terrain area, or the model is not fully visible to the attacker because of intervening terrain features or obscuring terrain areas. Against a unit with cover, worsen the attack's BS characteristic by 1.

Hidden

A model is Hidden while both apply: it is an INFANTRY, BEASTS or SWARM model within a terrain area that contains at least one Dense feature, and its unit made no ranged attacks during this turn or the previous turn. A Hidden model can only be seen by enemy models within its detection range, which is 15" unless a rule says otherwise.

Obscuring

Terrain areas that hold at least one Light or Dense feature count as obscuring terrain areas. Should every line of sight between two models pass through one or more obscuring areas — setting aside any obscuring area that one or both of those models occupy — the two models cannot see each other.

Solid

Dense features possess the Solid rule, which blocks line of sight through any enclosed gap in the feature's surface sitting no higher than 3" above ground level. This stops models sheltering at ground level from being seen through doors, windows or small gaps, regardless of those openings. Some missions adjust the height at which Solid takes effect.

Models that climb tall features gain superior sight lines and may qualify for the Plunging Fire rule when shooting down at targets below.

Frequently asked questions

What are the terrain categories in Warhammer 40,000 11th edition?

Every terrain feature is Exposed, Light or Dense. Exposed offers almost no protection and never slows models, Light can grant cover but does not hinder movement, and Dense can block large war machines and conceal whole units from sight.

How does the Benefit of Cover work in 40k?

A unit has the benefit of cover only if every model in it is either an INFANTRY, BEASTS or SWARM model within a terrain area, or is not fully visible because of intervening terrain or obscuring areas. Against a covered target, worsen the attack's BS characteristic by 1.

What is the detection range for a Hidden model in Warhammer 40,000?

A Hidden model can only be seen by enemy models inside its detection range, which is 15" unless a rule states otherwise. A model is Hidden while it is an INFANTRY, BEASTS or SWARM model in a terrain area containing a Dense feature and its unit made no ranged attacks this turn or last turn.

Can vehicles and monsters move through Dense terrain in 40k?

INFANTRY, BEASTS, SWARM and MOBILE models move horizontally through Dense terrain freely, but other models can only pass sections 2" or less in height and must climb anything taller. Such models also cannot pass through ceilings or floors, or finish a move above ground level.

What does the Solid rule do in Warhammer 40,000 11th edition?

Solid, carried by every Dense feature, stops line of sight passing through any enclosed gap in the feature's surface no higher than 3" above ground level. This stops models sheltering at ground level from being seen through doors, windows or small openings.