Hello, Guest! | Sign In | My Account | Shopping Cart | Help/FAQ Paizo Pathfinder® Paizo Games
 About Paizo Messageboards News Paizo Blog Help/FAQ

Paizo
Community
Store

# Radius from Square (not point / intersection); Second Look Appreciated

### Rules Questions

Hey folks,

Just want to make sure I have these spreads correct (currently running a game on a permanent dim light demiplane; writing an app to make sure I keep track of light in combat accurately).

http://i.imgur.com/evCWT.png

Also need to make a 40 radius template, but if the logic of these are correct it shouldn't be a problem.

Thanks.

Edit: Side question. If that 10 foot spread is correct, how does that work with reach weapons? By RAW, can reach 'reach' across two diagonal squares? How do you run it?

The problem is that radius templates are measured from the intersections rather than the 5foot square at the center. CRB p215 shows this.

- Gauss

Gauss wrote:

The problem is that radius templates are measured from the intersections rather than the 5foot square at the center. CRB p215 shows this.

- Gauss

Sure, but then how do you determine where a torch sheds light? Does the player choose which intersection they are holding the torch at? That seems non-intuitive.

I agree it is. For some things I still use square centering but that is a house rule.

- Gauss

Yeah...the rulebook unfortunately doesn't account for things that cause a radius from your square, like torch light, channel energy, rings of retribution and certain spells, so thanks, that page will see many uses by me in the future.

Whale_Cancer wrote:
Gauss wrote:

The problem is that radius templates are measured from the intersections rather than the 5foot square at the center. CRB p215 shows this.

- Gauss

Sure, but then how do you determine where a torch sheds light? Does the player choose which intersection they are holding the torch at? That seems non-intuitive.

Mechanically, by RAW, a torch illuminates the entire 5 foot square that it or its bearer occupies.

If you want to account for things like holding a torch at arm's length (which might very well be the edge of the square in front of the character) then you'll have to wing it.

I wouldn't go any deeper than edge-to-edge or center-to-center, though, else you're going way too deep into realistic lighting dynamics that just don't translate to a game measured in one-inch, 5-foot increments.

After all, what if the ceiling is low? The light would be brighter. Opposite effect for high ceilings. What if the wall is textured? Or absorbent of light? Or has luminescent fungus or moss on it? What if the character casts the "Light" spell on his boots? What if there are stalactites/mites in the way? How accurate do you REALLY want to take this?

When all else fails, best guess by the DM.

Not sure the page number, but CRB, magic, aiming a spell, area. That section states that any area effect goes from a grid intersection. So assuming that a torch goes off the same rules as area spells, it would illuminate four squares. Think of it as are you holding the torch in your left or right hand, and in front or behind you? Now pick the intersection that it corresponds to.

If you really want to measure from the center of a square, you have to go to the center of the squares on the edges, otherwise you are adding an extra five feet on each side. And if the effect doesn't cover 100% of the square it doesn't affect it at all, so measuring from the middle of the square you actually lose distance.

Maybe you should do what I do to get the lighting templates in MapTool to match up to the grid - add 2.5 feet to the radius of any effect you need a spread for that is centered in a square rather than centered on an intersection.

A torch would then cast normal light in a 22.5 foot radius, and increase the light level for another 20 feet (total of 42.5) beyond that.

Barry Armstrong wrote:
Mechanically, by RAW, a torch illuminates the entire 5 foot square that it or its bearer occupies.

Actually, by RAW " A torch burns for 1 hour, shedding normal light in a 20-foot radius and increasing the light level by one step for an additional 20 feet beyond that area (darkness becomes dim light and dim light becomes normal light)" so I am not sure what you are talking about.

Barry Armstrong wrote:
If you want to account for things like holding a torch at arm's length (which might very well be the edge of the square in front of the character) then you'll have to wing it.

I do not.

Barry Armstrong wrote:
I wouldn't go any deeper than edge-to-edge or center-to-center, though, else you're going way too deep into realistic lighting dynamics that just don't translate to a game measured in one-inch, 5-foot increments.

The question is what the radius of a torch looks like, since it should be centered on a square rather than an intersection. Since there is no facing in Pathfinder, the choice of grid intersection would be arbitrary (and therefore somewhat problematic).

Barry Armstrong wrote:
After all, what if the ceiling is low? The light would be brighter. Opposite effect for high ceilings. What if the wall is textured? Or absorbent of light? Or has luminescent fungus or moss on it? What if the character casts the "Light" spell on his boots? What if there are stalactites/mites in the way? How accurate do you REALLY want to take this?

I just want basic lighting to make sense to me so I can write a program to keep track of light during combat (I am using grid numbers in my program and on my map to correlate them). This is because I find that lighting often gets handwaved/ignored and it is a major part of the campaign I am currently running.

PurpleShirt wrote:
Not sure the page number, but CRB, magic, aiming a spell, area. That section states that any area effect goes from a grid intersection. So assuming that a torch goes off the same rules as area spells, it would illuminate four squares. Think of it as are you holding the torch in your left or right hand, and in front or behind you? Now pick the intersection that it corresponds to.

There is no facing in Pathfinder, so the intersection selection is arbitrary.

PurpleShirt wrote:
If you really want to measure from the center of a square, you have to go to the center of the squares on the edges, otherwise you are adding an extra five feet on each side. And if the effect doesn't cover 100% of the square it doesn't affect it at all, so measuring from the middle of the square you actually lose distance.

Hmmmmmmmmmmmmmmmmmmmmmm...... Damn. You have a point there. Maybe I should just institute the facing rules from 3.5s Unearthed Arcana... heh. I suspect I will just give torches that extra bit of distance from how my picture in the OP does the radius of a torch as any other option is prohibitively complex.

AaronOfBarbaria wrote:

Maybe you should do what I do to get the lighting templates in MapTool to match up to the grid - add 2.5 feet to the radius of any effect you need a spread for that is centered in a square rather than centered on an intersection.

A torch would then cast normal light in a 22.5 foot radius, and increase the light level for another 20 feet (total of 42.5) beyond that.

This is basically what I am doing, just not with map tools (I need grid coordinates to correspond to a physical map [I DM from behind a laptop])

Whale_Cancer wrote:
Edit: Side question. If that 10 foot spread is correct, how does that work with reach weapons? By RAW, can reach 'reach' across two diagonal squares? How do you run it?

Yes, reach weapons reach two diagonal squares. This is an exception to the 1, 2, 1 etc rule of counting diagonals, as without the exception you could simply approach from a diagonal to avoid the 10' reach of a creature.

littlehewy wrote:
Whale_Cancer wrote:
Edit: Side question. If that 10 foot spread is correct, how does that work with reach weapons? By RAW, can reach 'reach' across two diagonal squares? How do you run it?
Yes, reach weapons reach two diagonal squares. This is an exception to the 1, 2, 1 etc rule of counting diagonals, as without the exception you could simply approach from a diagonal to avoid the 10' reach of a creature.

That's the way I have always run it, but I wasn't aware that was specified by RAW.

Edit: Do you have a citation. That isn't measured in Diagonals or in Reach.

Hmmm not near my book, but this link has templates. It's the d20 site, so I'm not sure if this is Paizo endorsed, but it's been endorsed by James Jacobs (at least), which is enough for me :)

Reach weapons cannot reach the second diagonal by RAW. The rule that allowed them to do so is missing from PF. That rule was in the 3.5 PHB.

The missing rule from PHB p137 Threatened Squares section wrote:
However, Small and Medium creatures wielding reach weapons (such as a longspear) threaten more squares than a typical creature. For instance, a longspear-wielding human threatens all squares 10 feet (2 squares) away, even diagonally. (This is an exception to the rule that 2 squares of diagonal distance is measured as 15 feet.)

As already stated many people house rule this back into existence. The D20PFSRD reach templates are incorrect. They should note that this is a house rule template.

- Gauss

Gauss wrote:

Reach weapons cannot reach the second diagonal by RAW. The rule that allowed them to do so is missing from PF. That rule was in the 3.5 PHB.

The missing rule from PHB p137 Threatened Squares section wrote:
However, Small and Medium creatures wielding reach weapons (such as a longspear) threaten more squares than a typical creature. For instance, a longspear-wielding human threatens all squares 10 feet (2 squares) away, even diagonally. (This is an exception to the rule that 2 squares of diagonal distance is measured as 15 feet.)

As already stated many people house rule this back into existence. The D20PFSRD reach templates are incorrect. They should note that this is a house rule template.

- Gauss

Thanks Gauss! I always prefer to know what the rule is RAW before instituting any house rules.

Gauss wrote:
The D20PFSRD reach templates are incorrect. They should note that this is a house rule template.

What specifically is incorrect? They've been up for like 1-2 years and this is the first time I've heard they're not correct. If there is something not correct please make a point to let me/us know so we can fix it. It is not meant to be a houserule, it is meant to reflect our understanding of the actual rules.

Please explain the error so it can be corrected.

d20pfsrd.com:

The reach weapon templates posted here are using the 3.5 reach weapon exception rule. That rule has not been included in PF.

The rule missing from PF is:

PHB p137 Threatened Squares section wrote:
However, Small and Medium creatures wielding reach weapons (such as a longspear) threaten more squares than a typical creature. For instance, a longspear-wielding human threatens all squares 10 feet (2 squares) away, even diagonally. (This is an exception to the rule that 2 squares of diagonal distance is measured as 15 feet.)

Since that rule is missing it means that you count diagonals normally, 5' for the first, 15' for the second, even for reach weapons.

James Jacobs responds here that the second diagonal is measured just like other diagonal measurements.

It has been debated a number of places what happens when a creature approaches a reach weapon user on the diagonal. Here SKR indicates that even though you do not threaten the 15' distant square any creature moving from that 15' square to the 5' square do indeed suffer an attack of opportunity.

There have been many other threads on this topic and as I said earlier, many people houserule the 3.5 exception rule back into existance.

- Gauss

I updated the Medium and Large templates and added an Editor's Note. Do the templates reflect the current and correct rules then?

The second set of templates do. The first set (Medium, Large, Huge) do not.

Personally, I would keep a link to the original 3.5 way of doing it too. But if you do not list house rules, even extremely common ones, I understand.

- Gauss

P.S. Someone is probably going to hate me for pointing this out to you. :) Many people cite the d20pfsrd reach templates. It has been used in many threads.

Gauss, next time you see an inconsistency on d20pfsrd.com, you should send a 2 minute e-mail over to d20pfsrd+problems@gmail.com

At least I think that's the address.

If you ever see the phrase "Well, d20pfsrd.com is wrong."...do your part to make it right :D

d20pfsrd, just a note: the colossal templates are too small by one square at certain places.

- Gauss

Cheapy, Im surprised someone else hasn't done that. After all, I found this topic discussed over a year ago. At least one person (besides me) thought d20pfsrd was showing the 3.5 version on purpose.

- Gauss

Thanks Cheapy. That email works, but so does my personal address (jreyst@gmail.com.)

Yeah, we try to correct things whenever people bring them to our attention and are usually pretty quick about it... so long as someone tells us.

@Gauss: I need specifics, or alternatively I can give you edit access to the templates. They're just embedded Google Spreadsheets. All you need is a Google ID and the ability to change the color of a cell in a spreadsheet :)

Honestly, this is such a stealth house rule it isn't funny. Many people run it this way and are then surprised to find that it is a house rule.

- Gauss

Bah, I hate google. Hang on, let me see if I can write it out.

Colossal (regular) NW corner: If you count the squares heading straight out on the diagonal you end with 7squares (1, 3, 4, 6, 7). The next diagonal is 9 squares. No go. BUT, north from that last square is legal. So is west.

Repeat for the other diagonals.

- Gauss

 RPG Superstar 2015 Top 16, RPG Superstar 2013 Top 16

Radius of an effect is almost always counted from an intersection, not the center of a square. This is always true of spell effects. The effect's originator, such as the spell's caster, picks the intersection from which the effect originates.

Since continual flame is a spell effect and behaves this way, an everburning torch also behaves this way. Although it doesn't specifically state so in the rules, it makes sense for other light sources to behave the same way: if you're holding a torch, you pick a corner of your square and the light radius is centered on that intersection.

Reach isn't an area effect and therefore isn't an exception to radius of effects being figured from an intersection.

Charlie Bell wrote:
Radius of an effect is almost always counted from an intersection, not the center of a square. This is always true of spell effects. The effect's originator, such as the spell's caster, picks the intersection from which the effect originates.

Yup, this has been pretty much solved. If we were allowed to edit old posts, I would put 'solved' in the thread title.

Charlie Bell wrote:
Reach isn't an area effect and therefore isn't an exception to radius of effects being figured from an intersection.

Yup*

 RPG Superstar 2015 Top 16, RPG Superstar 2013 Top 16

Whoops, missed the solution amidst the reach weapon insanity.

Gauss wrote:

It has been debated a number of places what happens when a creature approaches a reach weapon user on the diagonal. Here SKR indicates that even though you do not threaten the 15' distant square any creature moving from that 15' square to the 5' square do indeed suffer an attack of opportunity.

This is an excellent ruling, and should be errata'd in.

In effect, SKR's ruling means that the reach weapon doesn't threaten the diagonal 15' square, so spellcasting or whatever doesn't provoke, but if you approach from that direction you still do provoke.

I like it, anyway.

Thanks for the clarifications Gauss. I'd say I was house ruling on the reach weapon threatening the square, but not on movement in provoking.

Whale_Cancer wrote:

Mechanically, by RAW, a torch illuminates the entire 5 foot square that it or its bearer occupies.

Actually, by RAW " A torch burns for 1 hour, shedding normal light in a 20-foot radius and increasing the light level by one step for an additional 20 feet beyond that area (darkness becomes dim light and dim light becomes normal light)" so I am not sure what you are talking about.

Yeah, me either. I am normally spot on with rules recollections. I must have been confused with another system. I sit corrected.

20' radius to me says that radius would be centered around the character or sconce holding the torch.

The easiest thing rules-wise to compare it to is a 20' spell radius, where the torch is in the center. Whether that's on a convenient grid line or intersection is up to the DM.

Pathfinder Adventure Path Charter Subscriber; Pathfinder Comics Subscriber; Pathfinder Campaign Setting, Cards, Companion, Maps, Modules, Roleplaying Game Subscriber

BUT WHAT IF I MAGIC MISSILE THE DARKNESS?

WHAT THEN???