We have this rule in the PHB, p. 204, about Areas of Effect:
A spell's effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn't included in the spell's area. To block one of these imaginary lines, an obstruction must provide total cover, as explained in chapter 9.
Taking Spirit Guardians as an example, does its Area of Effect extend through walls or total cover? I guess not, following that rule, similar to when you cast Fireball in an enclosed space.
So, in the next drawing with a room and an open door, should the dashed red squares be included in the affected area (EDIT: either totally or partially)? "PC" is the caster and the orange circle represents the spell.
I think that the reason that some spells like fireball say that they extend around corners is because by default the sentence you quote from the rule indicates that they do not. The effect extends in straight lines from the PC.
The two squares between the dashed red lines behind the door offer no cover, and then some of the squares in the red dashed boxes would be considered half or 3/4 cover according to the arrows in the DMG, but if i recall correctly, only Dex saves care about cover, so they'd still be in the area. I think three squares inside of the dashed boxes would still be hit by a straight line from the pc's space, so in the effect (in an L shape). The other three would not be affected.
The DMG provides some guidance for this on Page 251 in the sections called "Areas of Effect" and "Cover" (and some diagrams on nearby pages). Perhaps not intuitively, the rule from the DMG says that when using a grid and miniatures such as in your diagram in your original post, you actually choose an intersection of grid squares as your point of origin. This means that your orange circle is actually too large -- you need to have it be a radius of 3 squares away from one of the corners of the PC's location. Depending on which corner is chosen, this could impact which squares in the room are behind total cover -- there is a method given involving drawing lines from your chosen point of origin to each corner of the square in question to determine how much cover that square actually has, which determines whether or not that square is excluded from the AoE due to the rule you've quoted.
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.
COVER
To determine whether a target has cover against an attack or other effect on a grid, choose a corner of the attacker's space or the point of origin of an area of effect. Then trace imaginary lines from that corner to every corner of any one square the target occupies. If one or two of those lines are blocked by an obstacle (including another creature), the target has half cover. If three or four of those lines are blocked but the attack can still reach the target (such as when the target is behind an arrow slit), the target has three-quarters cover.
On hexes, use the same procedure as a grid, drawing lines between the corners of the hexagons. The target has half cover if up to three lines are blocked by an obstacle, and three-quarters cover if four or more lines are blocked but the attack can still reach the target.
@up2ng, I'm not asking about how to represent a circle on a grid for a certain Self (XYZ) AoE spell. My question is whether Self (XYZ) AoE spells can be extended through total cover.
And no, at my table, that orange circle is perfectly fine. As @WolfOfTheBees said: "A medium creature takes up its entire space, so within 15’ of it is a circle 35’ across."
Moderator Note: As the original poster has stated that they are not interested in the particular rule interaction between ranges, grids and points of origin for the purposes of their question, further discussion on such would be better taken to a new thread.
It seems like you already answered your own question within the original post with the rule that you quoted to go along with the question. There's nothing different about an AoE with a Range of Self. It still follows the same rules as other AoE spells which means that the effects would be blocked by total cover.
The two squares between the dashed red lines behind the door offer no cover, and then some of the squares in the red dashed boxes would be considered half or 3/4 cover according to the arrows in the DMG, but if i recall correctly, only Dex saves care about cover, so they'd still be in the area. I think three squares inside of the dashed boxes would still be hit by a straight line from the pc's space, so in the effect (in an L shape). The other three would not be affected.
This is basically correct for RAW, but there is some wiggle room if a DM wants to rule that a spell like aura of life -- which doesn't have targets and is just a blanket buff -- can ignore total cover completely
Total Cover
A target with total cover can’t be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle.
Generally that's interpreted to mean that a spell needs to carve out a specific exception (i.e. fireball with its "spreads around corners" line) to work around/through total cover, but you could make a case for something like an aura spell, I think
For me that's a tougher sell on spirit guardians -- if WotC wanted the "spectral" part of the description to have a mechanical effect like passing through walls, they probably would have said so
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Active characters:
Carric Aquissar, elven wannabe artist in his deconstructionist period (Archfey warlock) Lan Kidogo, mapach archaeologist and treasure hunter (Knowledge cleric) Mardan Ferres, elven private investigator obsessed with that one unsolved murder (Assassin rogue) Xhekhetiel, halfling survivor of a Betrayer Gods cult (Runechild sorcerer/fighter)
It would depend on the spell, but in general any target or location to which lines are blocked by total cover isn't included in the spell's area. I would expect the spell to specifically say so, such as Sacred Flame which ignore cover or Fireball and Delayed Blast Fireball that spreads around corners. Other spells may be subject to DM ruling on case by case basis.
I found this on RPG Stack Exchange today (Do auras require line of effect?). The accepted answer there is "Rules as written, no, auras don't require line of effect". (EDIT) I'm not sure After reading the latest answers here, I guess you guys rule differently.
To be honest, I'm not sure if spells with auras should follow the rules posted in the thread. For now, I have been ruling that aura spells are also blocked by total cover (e.g., a wall). However, it would be helpful if you know of any RAW or RAI for these cases.
I found this on RPG Stack Exchange today (Do auras require line of effect?). The accepted answer there is "Rules as written, no, auras don't require line of effect". (EDIT) I'm not sure After reading the latest answers here, I guess you guys rule differently.
To be honest, I'm not sure if spells with auras should follow the rules posted in the thread. For now, I have been ruling that aura spells are also blocked by total cover (e.g., a wall). However, it would be helpful if you know of any RAW or RAI for these cases.
Yeah, we're pretty much into Rule of Cool territory with the auras. Narratively though, it makes sense to me that if a cleric is radiating holy healing energy, their party member on the other side of a wall could still spring to consciousness after being knocked down to 0 hp. aura of vitality also specifically doesn't require you to be able to see someone to heal them, so it seems kind of silly to rule that you need line of sight to them
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Active characters:
Carric Aquissar, elven wannabe artist in his deconstructionist period (Archfey warlock) Lan Kidogo, mapach archaeologist and treasure hunter (Knowledge cleric) Mardan Ferres, elven private investigator obsessed with that one unsolved murder (Assassin rogue) Xhekhetiel, halfling survivor of a Betrayer Gods cult (Runechild sorcerer/fighter)
This is basically correct for RAW, but there is some wiggle room if a DM wants to rule that a spell like aura of life -- which doesn't have targets and is just a blanket buff -- can ignore total cover completely
Total Cover
A target with total cover can’t be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle.
Generally that's interpreted to mean that a spell needs to carve out a specific exception (i.e. fireball with its "spreads around corners" line) to work around/through total cover, but you could make a case for something like an aura spell, I think
The portion of that rule that you've highlighted in red is not really meant to provide wiggle room per se, it's just pointing out a consequence of how AoE spells work.
This is one of the two common scenarios where it becomes important to understand that the target of an AoE spell is its point of origin. (The other relevant common scenario has to do with affecting creatures outside of the spell's range.) The wording of the Total Cover rule uses the term "target" in a clumsy way, but what that rule is basically trying to say is this:
Suppose a creature is behind total cover with respect to the spellcaster. Let's say the spellcaster is walking along the outside of a castle wall with the castle on his left. Up ahead several feet away is the corner of the castle and you would eventually take a left turn to continue walking next to the castle. You suspect that there is a creature hiding up against that far wall around the corner from our location. Because of the clear path rule, you cannot target that creature with any spell. A spell like Magic Missile is worthless in that situation. However, you can still affect that creature with an AoE. You could target a point in space just beyond the corner of the castle and the resulting spherical AoE will expand outwards to include this creature's location quite easily. Note that the creature was still not targeted by a spell since that's not allowed.
The rule for Areas of Effect that was quoted by the OP uses the concept of Total Cover in a different way. In that case, it is talking about total cover with respect to the point of origin, not with respect to the spellcaster. It talks about drawing lines from the point of origin to a particular square within the area to see if there are unblocked lines which would indicate a lack of total cover. This all has to do with the concept of the effect spreading outwards in straight lines from the point of origin, so obstacles within the Area can cause slivers or potentially large portions of that area to become unincluded in the Area of Effect.
So, conversely to the above example, you could have a situation where a creature is in plain sight and could be easily directly targetable with a spell such as Magic Missile. But you've chosen to cast an AoE spell, targeting a point in space nearby. But, between that origin point and the creature is a large wooden crate. So, even though the creature didn't have any cover with respect to the spellcaster, it has total cover with respect to the AoE and is unaffected by it.
aura of vitality also specifically doesn't require you to be able to see someone to heal them, so it seems kind of silly to rule that you need line of sight to them
I see what you're getting at with the Rule of Cool with these spells, but just in terms of the rules this wouldn't be a question of line of sight (although the path in question is similar for "self" AoE spells) -- it's a matter of the fact that AoE effects spread outwards from the point of origin ("radiates from you") and so the path from the point of origin to the creature could be blocked.
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We have this rule in the PHB, p. 204, about Areas of Effect:
Taking Spirit Guardians as an example, does its Area of Effect extend through walls or total cover? I guess not, following that rule, similar to when you cast Fireball in an enclosed space.
So, in the next drawing with a room and an open door, should the dashed red squares be included in the affected area (EDIT: either totally or partially)? "PC" is the caster and the orange circle represents the spell.
Should the same rule be applied to spells with auras, such as Aura of Life or Aura of Vitality?
I think that the reason that some spells like fireball say that they extend around corners is because by default the sentence you quote from the rule indicates that they do not. The effect extends in straight lines from the PC.
The two squares between the dashed red lines behind the door offer no cover, and then some of the squares in the red dashed boxes would be considered half or 3/4 cover according to the arrows in the DMG, but if i recall correctly, only Dex saves care about cover, so they'd still be in the area. I think three squares inside of the dashed boxes would still be hit by a straight line from the pc's space, so in the effect (in an L shape). The other three would not be affected.
The DMG provides some guidance for this on Page 251 in the sections called "Areas of Effect" and "Cover" (and some diagrams on nearby pages). Perhaps not intuitively, the rule from the DMG says that when using a grid and miniatures such as in your diagram in your original post, you actually choose an intersection of grid squares as your point of origin. This means that your orange circle is actually too large -- you need to have it be a radius of 3 squares away from one of the corners of the PC's location. Depending on which corner is chosen, this could impact which squares in the room are behind total cover -- there is a method given involving drawing lines from your chosen point of origin to each corner of the square in question to determine how much cover that square actually has, which determines whether or not that square is excluded from the AoE due to the rule you've quoted.
[Redacted] A medium creature takes up its entire space, so within 15’ of it is a circle 35’ across.
@up2ng, I'm not asking about how to represent a circle on a grid for a certain Self (XYZ) AoE spell. My question is whether Self (XYZ) AoE spells can be extended through total cover.
And no, at my table, that orange circle is perfectly fine. As @WolfOfTheBees said: "A medium creature takes up its entire space, so within 15’ of it is a circle 35’ across."
Moderator Note: As the original poster has stated that they are not interested in the particular rule interaction between ranges, grids and points of origin for the purposes of their question, further discussion on such would be better taken to a new thread.
Ok that's cool if you guys play it like that.
It seems like you already answered your own question within the original post with the rule that you quoted to go along with the question. There's nothing different about an AoE with a Range of Self. It still follows the same rules as other AoE spells which means that the effects would be blocked by total cover.
This is basically correct for RAW, but there is some wiggle room if a DM wants to rule that a spell like aura of life -- which doesn't have targets and is just a blanket buff -- can ignore total cover completely
Generally that's interpreted to mean that a spell needs to carve out a specific exception (i.e. fireball with its "spreads around corners" line) to work around/through total cover, but you could make a case for something like an aura spell, I think
For me that's a tougher sell on spirit guardians -- if WotC wanted the "spectral" part of the description to have a mechanical effect like passing through walls, they probably would have said so
Active characters:
Carric Aquissar, elven wannabe artist in his deconstructionist period (Archfey warlock)
Lan Kidogo, mapach archaeologist and treasure hunter (Knowledge cleric)
Mardan Ferres, elven private investigator obsessed with that one unsolved murder (Assassin rogue)
Xhekhetiel, halfling survivor of a Betrayer Gods cult (Runechild sorcerer/fighter)
It would depend on the spell, but in general any target or location to which lines are blocked by total cover isn't included in the spell's area. I would expect the spell to specifically say so, such as Sacred Flame which ignore cover or Fireball and Delayed Blast Fireball that spreads around corners. Other spells may be subject to DM ruling on case by case basis.
Thanks AntonSirius. That's why I also asked for opinions about Aura of Life or Aura of Vitality.
I found this on RPG Stack Exchange today (Do auras require line of effect?). The accepted answer there is "Rules as written, no, auras don't require line of effect". (EDIT)
I'm not sureAfter reading the latest answers here, I guess you guys rule differently.To be honest, I'm not sure if spells with auras should follow the rules posted in the thread. For now, I have been ruling that aura spells are also blocked by total cover (e.g., a wall). However, it would be helpful if you know of any RAW or RAI for these cases.
Yeah, we're pretty much into Rule of Cool territory with the auras. Narratively though, it makes sense to me that if a cleric is radiating holy healing energy, their party member on the other side of a wall could still spring to consciousness after being knocked down to 0 hp. aura of vitality also specifically doesn't require you to be able to see someone to heal them, so it seems kind of silly to rule that you need line of sight to them
Active characters:
Carric Aquissar, elven wannabe artist in his deconstructionist period (Archfey warlock)
Lan Kidogo, mapach archaeologist and treasure hunter (Knowledge cleric)
Mardan Ferres, elven private investigator obsessed with that one unsolved murder (Assassin rogue)
Xhekhetiel, halfling survivor of a Betrayer Gods cult (Runechild sorcerer/fighter)
The portion of that rule that you've highlighted in red is not really meant to provide wiggle room per se, it's just pointing out a consequence of how AoE spells work.
This is one of the two common scenarios where it becomes important to understand that the target of an AoE spell is its point of origin. (The other relevant common scenario has to do with affecting creatures outside of the spell's range.) The wording of the Total Cover rule uses the term "target" in a clumsy way, but what that rule is basically trying to say is this:
Suppose a creature is behind total cover with respect to the spellcaster. Let's say the spellcaster is walking along the outside of a castle wall with the castle on his left. Up ahead several feet away is the corner of the castle and you would eventually take a left turn to continue walking next to the castle. You suspect that there is a creature hiding up against that far wall around the corner from our location. Because of the clear path rule, you cannot target that creature with any spell. A spell like Magic Missile is worthless in that situation. However, you can still affect that creature with an AoE. You could target a point in space just beyond the corner of the castle and the resulting spherical AoE will expand outwards to include this creature's location quite easily. Note that the creature was still not targeted by a spell since that's not allowed.
The rule for Areas of Effect that was quoted by the OP uses the concept of Total Cover in a different way. In that case, it is talking about total cover with respect to the point of origin, not with respect to the spellcaster. It talks about drawing lines from the point of origin to a particular square within the area to see if there are unblocked lines which would indicate a lack of total cover. This all has to do with the concept of the effect spreading outwards in straight lines from the point of origin, so obstacles within the Area can cause slivers or potentially large portions of that area to become unincluded in the Area of Effect.
So, conversely to the above example, you could have a situation where a creature is in plain sight and could be easily directly targetable with a spell such as Magic Missile. But you've chosen to cast an AoE spell, targeting a point in space nearby. But, between that origin point and the creature is a large wooden crate. So, even though the creature didn't have any cover with respect to the spellcaster, it has total cover with respect to the AoE and is unaffected by it.
I see what you're getting at with the Rule of Cool with these spells, but just in terms of the rules this wouldn't be a question of line of sight (although the path in question is similar for "self" AoE spells) -- it's a matter of the fact that AoE effects spread outwards from the point of origin ("radiates from you") and so the path from the point of origin to the creature could be blocked.