There has been a little bit of confusion on how to measure the radius of an effect when counting zones on a map in the Legendary Battles, so we clarified it better in the base rules.
Essentially, when determining the radius of an effect (such as for artillery, smoke, etc.) the zone the effect originates in (e.g. the Target Point, etc.) is not counted as part of the radius distance. Thus when determining an artillery barrage with an effect radius of two zones you would begin counting as you normally would for any other movement, range, etc. with the first zone adjacent to the Target Point.
The Distances section of the rules in the Free Download section have been updated to reflect this.