Breath Weapon Line?

[Ogrork the Mighty]

Under Dragon in the MM it states that a line breath weapon is 5 feet high by 5 feet wide.

I thought I read somewhere that a line affects the squares on both sides of a grid line (i.e., two 5-foot spaces on either side of the grid line).

From the SRD:
A line-shaped spell shoots away from you in a line in the direction you designate. It starts from any corner of your square and extends to the limit of its range or until it strikes a barrier that blocks line of effect. A line-shaped spell affects all creatures in squares that the line passes through.

So are breath weapons and line spell effects treated differently?

 

[frankthedm]

So are breath weapons and line spell effects treated differently?

Depends how the DM wants to run it. That MM text is probably copy and paste from 3.0 and the rules text for Lines and the example of Lines in the 3.5 PHB disagree.

GM is just going to have to pick one or base it off how big the dragon is.

• A Line that affects whatever squares it passes through.
• A Line that affects whatever squares it passes through or touches.
• A one inch thick "Line" that affects whatever squares it passes through.
• A one inch thick "Line" that affects whatever squares it passes through or touches.

PHB text: "A line-shaped spell affects all creatures in squares that the line passes through."
PHB Example's text: "All squares through which the line passes or touches are affected by the attack."




Skip Williams touched on this out in a ROTG article...

Line: A line's point of origin is one corner of the caster's space. (If the caster's space fills more than one square, you can use the optional rule suggested for cones to select the point of origin.) The line extends from the point of origin in any direction the caster chooses and reaches as far as the spell's range (or until its line of effect is blocked). The rules regarding lines are somewhat muddled; however, a line affects anything in a square that the line passes though or touches. So, if you send a line straight down a gridline, it will affect the squares to either side of the line. Some people like to limit a line's effects to a width of 5 feet. If so, the caster chooses which side of the line gets affected when a line passes between two squares. (Choose a side when you aim the spell, and once you choose, you have to stick with that side.)

Tangent; Sadly pathfinder went with the weaker "passes trough" line interpretation.

 

[FEADIN]

We play a 5' wide line and nothing more, you can cut a paper to have a shape and see on the map, every miniature touched by the paper is affected.