hi all, when i use my dragon breath (5'wide 30'long) i normally pick a square and follow it for 6 squares to determine targets, but another player has told me i can use the line between the squares. this would mean it would cover half of each square either side and per the rules affect creatures in them, this seems a little off to me as it means i then can double the amount of targets because it now affects 12 squares. is this a cheat or an intended effect? not sure this feels right.
Our DM uses a plastic template. you pick the direction then lay down the template. If it goes through at least half of the miniature that character is affected. Allows specific aiming but keeps it from targeting extra spaces. (Basically if it hits less than half the figure it is as if the character was in the "untargeted" area of the square at the time) Makes placement of figures important and sometimes leads to "friendly fire" if the caster is off on his aim.
For example, at my table, this would be a dragon's breath 5 feet wide and 30 feet long, but the player could choose a different angle too. We use the rules in XGtE (Template Method) to determine the affected creatures.
When using miniatures on a grid, by default the point of origin for all Areas of Effect created by any spell is placed on a grid intersection of squares (from the DMG):
AREAS OF EFFECT
The area of effect of a spell, monster ability, or other feature must be translated onto squares or hexes to determine which potential targets are in the area and which aren't.
Choose an intersection of squares or hexes as the point of origin of an area of effect, then follow its rules as normal. If an area of effect is circular and covers at least half a square, it affects that square.
The rules as normal for a Line are found in the PHB, Chapter 10:
Line
A line extends from its point of origin in a straight path up to its length and covers an area defined by its width.
A line's point of origin is not included in the line's area of effect, unless you decide otherwise.
To determine whether or not a grid square is in the AoE, the above rule from the DMG only provides guidance for circular areas. For others, it might be useful to use the rules from Xanathar's Guide to Everything. That text provides the "Template Method" and the "Token Method". As it turns out, these two methods can yield vastly different results for a Line AoE.
The Token Method generally restricts a Line to be positioned either orthogonally or diagonally, and the resulting example graphics show an affected area similar to what you've suggested in the OP that you were using -- affecting just 6 squares in both cases.
The Template Method allows the Line to be positioned along any possible angle and the rules for the Template Method are very generous about which squares are affected:
take note of which squares it covers or partially covers. If any part of a square is under the template, that square is included in the area of effect. If a creature’s miniature is in an affected square, that creature is in the area.
Although there are no graphic examples of a Line AoE using Templates, there is an example of a Cone AoE using Templates which clearly places the point of origin at a grid intersection at one of the corners of the spellcaster's square and then projects outwards away from the spellcaster from there.
Under these rules, if a Line AoE is placed orthogonally using the Template Method then 12 squares would be affected. If a Line AoE is placed diagonally using the Template Method then 15 squares would be affected. It might be possible to place the template at an unusual angle in order to affect even more squares than this.
hi all, when i use my dragon breath (5'wide 30'long) i normally pick a square and follow it for 6 squares to determine targets, but another player has told me i can use the line between the squares. this would mean it would cover half of each square either side and per the rules affect creatures in them, this seems a little off to me as it means i then can double the amount of targets because it now affects 12 squares. is this a cheat or an intended effect? not sure this feels right.
Our DM uses a plastic template. you pick the direction then lay down the template. If it goes through at least half of the miniature that character is affected. Allows specific aiming but keeps it from targeting extra spaces. (Basically if it hits less than half the figure it is as if the character was in the "untargeted" area of the square at the time) Makes placement of figures important and sometimes leads to "friendly fire" if the caster is off on his aim.
The DM decides if area of effect snap to grid in his game.
If they don't, then it's possible to have a dragon's breath weapon being 30-foot line that is 5 feet wide affect 2 squares large.
A few days ago, @alexdohm9191 asked a question about AoE mechanics, which I think is relevant to your question.
In that post, you can see examples and what the PHB, DMG, or XGtE say about this matter.
For example, at my table, this would be a dragon's breath 5 feet wide and 30 feet long, but the player could choose a different angle too. We use the rules in XGtE (Template Method) to determine the affected creatures.
When using miniatures on a grid, by default the point of origin for all Areas of Effect created by any spell is placed on a grid intersection of squares (from the DMG):
The rules as normal for a Line are found in the PHB, Chapter 10:
To determine whether or not a grid square is in the AoE, the above rule from the DMG only provides guidance for circular areas. For others, it might be useful to use the rules from Xanathar's Guide to Everything. That text provides the "Template Method" and the "Token Method". As it turns out, these two methods can yield vastly different results for a Line AoE.
The Token Method generally restricts a Line to be positioned either orthogonally or diagonally, and the resulting example graphics show an affected area similar to what you've suggested in the OP that you were using -- affecting just 6 squares in both cases.
The Template Method allows the Line to be positioned along any possible angle and the rules for the Template Method are very generous about which squares are affected:
Although there are no graphic examples of a Line AoE using Templates, there is an example of a Cone AoE using Templates which clearly places the point of origin at a grid intersection at one of the corners of the spellcaster's square and then projects outwards away from the spellcaster from there.
Under these rules, if a Line AoE is placed orthogonally using the Template Method then 12 squares would be affected. If a Line AoE is placed diagonally using the Template Method then 15 squares would be affected. It might be possible to place the template at an unusual angle in order to affect even more squares than this.
You can solve this issue by using hex battle maps instead of grid.
No Gaming is Better than Bad Gaming.
While not official ruling per se, if it's ever of use to you there was a Dev tweet about AOE grid placement of Cloud of Daggers (5-foot cube) Using 5ft squares, does "Cloud of Daggers" affect a single square? (sageadvice.eu)