Diagonal area of spells

[Oofta]

@Oofta

I'm curious if you're aware of the passage in the DMG p. 251 under Areas of Effect: "If an area of effect is circular and covers at least half a square, it affects that square." Following this guidance produces snap-to-grid templates slightly more generous than the images you posted.

Yeah, any template like this is going to be a compromise, it's not simple to put a circle in squares and have it make sense. A better option is hexes, but that's not very common.

 

[Nevvur]

Yeah, any template like this is going to be a compromise, it's not simple to put a circle in squares and have it make sense. A better option is hexes, but that's not very common.

For sure. No grid system has ever been perfect. I do a lot of grid-based play, but it's a hybrid of free-aiming and snap-to-grid mechanics that gives people with area effects a little more maneuverability. Although the DMG line I quoted only calls out circle effects, I use the same principle when adjudicating other areas, including the diamond-shaped cube as described by the OP.

I could always pull out rulers, geometry, and calculus if I wanted to get hardcore about the 50% coverage rule, but I know none of my players care that much, and neither do I. A quick visual examination suffices, and I'll err toward the players' benefit most of the time if there's any ambiguity.

--

A side note, not specifically at you, Oofta, I just don't see the potential for abuse in the situation the OP describes. I'm curious to know more about this powergamer player of his. If the guy has a history of seeking exploits, I understand wanting to curtail the behavior, but this issue seems like a strange line in the sand to draw.

 

[Tony Vargas]

. If the guy has a history of seeking exploits, I understand wanting to curtail the behavior, but this issue seems like a strange line in the sand to draw.

Powergamers can have that effect on DMs, you start to just assume anything they try is a ploy and want to just shut them down preemptively...

 

[balam_br]

Thanks for all the answers guys!
Its difficult to understand RAW in this case for me.... in DMG theres this text about area of effects in grids... (pg 251)
"The area of effect of a spell must be translated onto squares or hexes to determine which potential targets are in the area and which are not"
So, i assume you cant just use an spell effect that affects half of a square or any kind of area that does not respect the grid...

About the spell, its Psychic crush... a Mystic effect from Unhearted Arcana.

 

[Satyrn]

Thanks for all the answers guys!

. . .Its difficult to understand RAW in this case for me....

I'd say you should forget that RAW exists. I don't mean to forget that the rules exist, just the idea that there's one canonically correct interpretation of the rules.

You have the authority - and the responsibility - as the DM to choose the correct interpretation for your table. If, as you say, you "assume you cant just use an spell effect that affects half of a square or any kind of area that does not respect the grid..." I think you should make that your interpretation. Your ruling.

I also happen to think it's the way to go

 

[Oofta]

Thanks for all the answers guys!
Its difficult to understand RAW in this case for me.... in DMG theres this text about area of effects in grids... (pg 251)
"The area of effect of a spell must be translated onto squares or hexes to determine which potential targets are in the area and which are not"
So, i assume you cant just use an spell effect that affects half of a square or any kind of area that does not respect the grid...

About the spell, its Psychic crush... a Mystic effect from Unhearted Arcana.

I've pretty much always used a grid and have never had any problem adjusting spells to fit. The important thing to remember is that any representation of space and how people are positioned is just an approximation. While I posted previously about templates, you can use the same thing for any spell I've seen cast.

For squares/cubes I simply rule that it has to be a square on the grid, if it were cast at a diagonal it would be a cone.

 

[Hussar]

I gotta admit that this is one of my proud nail moments in 5e. I hate it when casters do it. It just bugs the heck out of me. I think it's cheesy. Yes, it's perfectly fine by the rules, but... well... my but isn't all that rational and I think I might be talking out of it.

I do think that 4e had the right of it. 1:1 counting and be done with it. Yes, for the 2 seconds that a fireball is on the table, it's square, but, that resolves so many of the niggling "Oh, if I shift this over 5 feet, it might get that guy, but that other guy is going next in initiative, so I should shift it over there" Mickey Mouse crap that I see at the table.

 

[Yaarel]

Heh. Great cubes of fire!

Fortunately mind-style easily visualizes circles, so its a nonissue.

If I was ever using a grid, I would either explicitly convert everything into squares, or else use a piece of string to pull around for the circle.

 

[Hussar]

The truly funny thing is, while my group absolutely insists on pixelated fireballs, they have zero problem with movement being 1:1. GARGH!H!HH! Makes my inner geek rage.

I get that 11 is more accurate than 1:1, but, if you're just going to cross the streams, then someone's getting wet.

 

[Satyrn]

Heh. Great cubes of fire!

Fortunately mind-style easily visualizes circles, so its a nonissue.

If I was ever using a grid, I would either explicitly convert everything into squares, or else use a piece of string to pull around for the circle.

This is odd, since the OP's issue is with a square area of effect instead of a circle.