We use Barrage templates to determine the area of effect for certain weapons.
When the rules tell you when to place a Barrage template as part of a game effect, use these conventions.
Placement of a Barrage template
When the rules tell you to place a Barrage template you must place it such that it is completely within range and line of fire of the shooting unit.
|Units that have the Artillery ability benefit from the Indirect Fire rule — so they do not need a line of fire.|
Coverage of units with a Barrage template
A unit is 'covered by' or 'under' the template when any one of these conditions is true:
Infantry unit: The centre of the unit’s base is under the template or touched by the edge of the template. 
Vehicle or War Engine unit: Any part of the unit’s base is under the template or touched by the edge of the template.
1. Difference from Epic 40,000: In Epic 40,000, coverage of Infantry units depends on the number of individual models on the base. We use the centre of the Infantry unit’s base instead, to account for the wide variation in number of models that players place on their Infantry unit bases.