Hi. If I cast a fireball, I assume I can cast it near a wall so the "effective" area of effect is shaped like a half circle.
What we are wondering is if you can do the same to a spell with this wording "XXX fills a 20 foot square on ground that you can see within range". It could sound like you need to see a full 20 feet square to be able to cast it. The spell in question is Black tentacles
I think it is very dependant on DM ruling. IIRC there is no specific rule addressing the need or not to have the full area of effect of a spell be "free".
That being said, you might want to remove the roll20 link, since it might be considered a competitor link.
I think I read that 5e area of effect spells only fill the available area if part of what would be AoE is obstructed. So if a full 20 foot square wasn't available for Black Tentacles it would fill as much of that area as was open. That is certainly how I would play it.
I don't really like the idea of not being able to cast an AoE spell just because part of the area is obstructed. I would rather say that the spell takes only partial effect in the unobstructed area.
"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."
Bolded and underlined for emphasis--there can be locations that are within the AoE that are not in the 'spell's effect area' due to obstructions.
So Darkness won't go through walls to make part of the next room over dark, but you can still cast it in a 10' radius room. Fireball in a 10' wide corridor will stop at the walls and extend 20' in either direction from the point of origin (although I could see a house rule expanding the radius along the hallway for a fireball if the corridor is narrower...but that may be too complicated of a rule for 5e's system to bother with).
Hi. If I cast a fireball, I assume I can cast it near a wall so the "effective" area of effect is shaped like a half circle.
What we are wondering is if you can do the same to a spell with this wording "XXX fills a 20 foot square on ground that you can see within range". It could sound like you need to see a full 20 feet square to be able to cast it. The spell in question is Black tentacles
Thanks.
I think it is very dependant on DM ruling. IIRC there is no specific rule addressing the need or not to have the full area of effect of a spell be "free".
That being said, you might want to remove the roll20 link, since it might be considered a competitor link.
Here's the DDB link to Black Tentacles
Born in Italy, moved a bunch, living in Spain, my heart always belonged to Roleplaying Games
Good point, done.
I think I read that 5e area of effect spells only fill the available area if part of what would be AoE is obstructed. So if a full 20 foot square wasn't available for Black Tentacles it would fill as much of that area as was open. That is certainly how I would play it.
I don't really like the idea of not being able to cast an AoE spell just because part of the area is obstructed. I would rather say that the spell takes only partial effect in the unobstructed area.
You just need line of sight to the point of origin.
This is from p204 of the PHB:
"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."
Bolded and underlined for emphasis--there can be locations that are within the AoE that are not in the 'spell's effect area' due to obstructions.
So Darkness won't go through walls to make part of the next room over dark, but you can still cast it in a 10' radius room. Fireball in a 10' wide corridor will stop at the walls and extend 20' in either direction from the point of origin (although I could see a house rule expanding the radius along the hallway for a fireball if the corridor is narrower...but that may be too complicated of a rule for 5e's system to bother with).
Looking for new subclasses, spells, magic items, feats, and races? Opinions welcome :)