Line Spells / Lightning Bolt

[TaranTheWanderer]

[MENTION=15882]TaranTheWanderer[/MENTION] - thanks for this. I was actually asking both and your diagram definitely helped clarify this to me!

I appreciate everyone's response to this.

No problem. And just for clarification's sake: for lightning bolt, since it is only a 5 foot wide effect, you'd only use the two top diagrams to adjudicate the line of effect.

If you had some kind of meta-magic effect that made lightning bolt into a 10 foot wide effect, you could use the bottom two diagrams. (off the top of my head, I can't think of a 10 foot wide line of effect spell...I'm sure there's a few. Blue Dragon's breath, maybe?

edit: Gust of Wind! 10 foot wide, 60 foot Line

 

[Shiroiken]

I do not force players to follow the guidelines in the DMG for casting spells on a grid. It breaks the verisimilitude for me, as I prefer to play TotM. At one point I actually considered using 2.5 ft squares to allow for such nuance, but unfortunately everyone is already accustomed to 5 ft squares, making the switch too annoying for my players. Instead I created a bunch of templates, and allow them to be used to determine the AoE.

Allowing it does make some abilities stronger, but to offset that I usually grant advantage on saves for those not in a fully affected square. This works both ways, for and against the players, so it hasn't caused any major imbalance.

 

[S'mon]

If you insist on casting in between two foes each 5' apart, I guess I'd likely give each a 50% chance of being hit.

 

[Dax Doomslayer]

If you insist on casting in between two foes each 5' apart, I guess I'd likely give each a 50% chance of being hit.

Yeah, I was thinking that each would get Advantage on their saves or something to that effect if we were to go that route...

 

[Oofta]

The 5 ft square is an abstraction for placement. Some creatures are going to be practically next to each others, others are gong to be more than 5 ft apart. So I'd agree with the 50% chance of hitting someone on either side.

 

[Blue]

Lightning bolt is 5' wide. In a 10' corridor there's no problems doing it down the middle with 2 1/2 feet on either side of it. 2.5' is not enough room for a medium or small sized creature (unless they were possibly already squeezing) so it would hit ones on both sides.

That said, there are rules for grid play and a common, oft unconscious, impulse is "snapping" all effects to the grid. So that a 5' line must go down one 5' half of a corridor or another. Mind you that plenty of other spells, especially radius, hit those that are partially in it, so this is a hidden nerf to line (and possibly cone) spells if required.

On the other hand I've played with plenty of DMs over years (and editions) who do not require snapping effects to the grid. The best judge of those I've seen used a cool set of clear plastic spell area templates that you just lay down on the map wherever you want and it's obvious who's in the AoE or not. So even with grids this is not a given.

 

[WhosDaDungeonMaster]

Hi Folks,
Quick question. Can a lightning bolt cast effectively act as 10' wide on a square grid? Looking at Xanthar's (p. 87 Diagram 2.6), it essentially looks like this is a way to adjudicate it. Essentially, someone casting a lightning bolt down the grid line so it goes half into both adjoining squares. How do you normally judge this? Thanks.

The diagram in Xanthar's shows how it is only supposed to be 5' wide. Likely the diagram you refer to is for the 10' wide effects (the bottom right-hand placement), the one above that is for 5 feet wide. It shows shows this is along the 45 degree diagonal (see Figure 1, only hitting target 2). However, this is rather limiting and you probably don't want to only be able to shoot along diagonals, so there are options you might want to consider:

First is the straight line. Using a ruler, yardstick, or string, you draw a straight line from the origin to the end point. ANY portion of a square that line passes through is affected. In Figure 2, that would be targets 2, 4, and 5. This allows for optimal placement.

The second option is the pattern (Figure 3). Each movement to the right from origin character "T" is allowed 1 square to occupy and must have a common corner point. The pattern must repeat. In this example, the lightning bolt would hit targets 4 and 5.



Different DMs use other methods, but options such as these are pretty common. Hope that helps.

 

[WhosDaDungeonMaster]

Lightning bolt is 5' wide. In a 10' corridor there's no problems doing it down the middle with 2 1/2 feet on either side of it. 2.5' is not enough room for a medium or small sized creature (unless they were possibly already squeezing) so it would hit ones on both sides.

That said, there are rules for grid play and a common, oft unconscious, impulse is "snapping" all effects to the grid. So that a 5' line must go down one 5' half of a corridor or another. Mind you that plenty of other spells, especially radius, hit those that are partially in it, so this is a hidden nerf to line (and possibly cone) spells if required.

On the other hand I've played with plenty of DMs over years (and editions) who do not require snapping effects to the grid. The best judge of those I've seen used a cool set of clear plastic spell area templates that you just lay down on the map wherever you want and it's obvious who's in the AoE or not. So even with grids this is not a given.

I've allowed this scenario as well, but inform the player "splitting" the edge along the gridlines will allow enough space (that 2.5 feet on each side), that any medium or smaller target will get advantage on their save. Likewise with cone-effects, things on the far edge might get advantage on those saves. But, that's just how we do it.

 

[Dax Doomslayer]

It's a little more trickier on a VTT. If I was on a combat map, it probably wouldn't be a problem as I have templates for this. I may allow it but give those that square isn't more than 3/4 affected advantage on their saving throw. I appreciate the diagrams above [MENTION=6976296]James Grover[/MENTION]!

 

[WhosDaDungeonMaster]

It's a little more trickier on a VTT. If I was on a combat map, it probably wouldn't be a problem as I have templates for this. I may allow it but give those that square isn't more than 3/4 affected advantage on their saving throw. I appreciate the diagrams above [MENTION=6976296]James Grover[/MENTION]!

No problem. Ruling less than 3/4 coverage advantage is a good way to go if it works for your group.