Reach and AoO's: Cross, or Square?

[Olgar Shiverstone]

I decided to eliminate confusion, and just make a set of templates for reach and areas of effect. I made up some Powerpoint slides that had a 1" grid, then marked off the appropriate areas. I then printed them to transparencies and cut them out -- easy!

I'm going to use the corners for 10' reach, incidentally, to avoid the diagonal problem.

Another observation: the Fireball template from Dragon 301 is wrong. It cuts off three squares -- it only has a 15' radius on the diagonal, instead of a 20' radius. The real 20" radius has a "fatter" apprearance and includes three additional squares at diagonal distances.

 

[Negative Zero]

interestingly enough, Olgar's comment got me thinking. (a notoriously bad idea i know, but what's done is done ) assuming that the normal 5 feet of reach that the average PC has theoreticaly starts in the center of his square, then it only extends halfway into the adjacent 8 squares. this leads to the conclusion that as long as half a square is affected then the entire square is affected.

therefore, in the case of the second diagonal, only about 2.6 feet (of the 7.4 feet distance of the diagonal as commented by Caliban) is really affect by a creature with 10 feet of reach. since that's not enough to cover half of the square, then that square isn't affected ... right?

see? i told you that getting me thinking wasn't a good idea!

~NegZ

 

[Negative Zero]

as an addendum to the above:

the assumption is that a character will constantly move about his own square throughout his round and the only way to keep an average is to assume the center for all attacks

~NegZ

 

[Stalker0]

From the faq ruling, the correct way is to not allow attacks in to the diaganols, but allowing AOO for attacking move in through the diagonals.

That's the ruling.

I personally go with allowing all squares because its more convient for me.

And speaking as someone studying to be an engineer, the meter to feet conversion is a pain in teh butt!!!

 

[IceBear]

That's why I did electrical engineering in Canada - no conversions and very little distance related measurements anyway

IceBear

 

[Pax]

I actually have considered a 50/50 roll like that for the edge of spell areas. On the one hand, it would be nice to have a bit of unpredictability as casters try to perfectly situate their blasty spells. On the other hand, it would be one more roll/complication to slow the action down.

Here's an alternate way to handle that:

Give the target the equivalent of a Cover Bounis to AC, based on what fraction of the square they occupy is NOT directly threatened, or affected by the spell.

So if you are in a square that is 33% "threatened", you have roughly 2/3 "cover" from the attack.

This works against spells as well, because there is a reflex save bonus involved (for other save types, you can rule that being touched at ALL brings the full effects, so physical location is irrelevant for Fortitude or Will save spells).

You just have to pre-plan which squares ont eh edge of a given radius effect have what % effected, the inverse of which is their relative cover level.

If the subject actually HAS cover, simply ADD the fractions together ... so someone with 1/3 cover, in a square only 1/3 affected by a spell of threatened by a weapon, essentially has FULL cover, and is not attackable / affectable by the spell or weapon in question.

Note that this works as well for people too CLOSE, on a diagonal, to a reach weapon as well.

...

However, I think this adds another, potentially unneccessary, level of complexity. But IMO, it'd be the simplest, cleanest way to handle "I can reach PART of the square but not ALL of it" questions; applied equally to edges of radial (and possibly other, like CONE area) SPELLS, and to radial issues of REACH WEAPONS ... most players should at least agree it's FAIR.

 

[mkletch]

Officially 2 diagonals away is 15' and you can't attack there with 10' of reach.

This is correct. But it really depends on how you do movement. If you allow any number of diagonal moves to be 5' each, then it should be the same for reach. If you use the official version for movement (which does slow things down), then you should use the official version for reach. The key, IMHO, is to be consistent.

Note that the '2 diagonals = 15 ft.' gives you a quick way to determine spell areas.

-Fletch!

 

[The Souljourner]

I generally prefer to change geometry in my D&D worlds such that a square's diagonal is the same length as its sides. This nips all these problems in the bud.

Oh... and about reach weapons not being able to attack on the diagonal - stupidest thing I ever heard.

Oh, one more thing... if 2 squares away on a diagonal is 15'... does that mean you can't take 5' steps across diagonals? Only makes sense, right? 15' away, take a 5' step, 10' away.

-The Souljourner

 

[Olgar Shiverstone]

Of course, you can switch to hexes and avoid all this silliness, since the distance between the centers of any two adjacent hexes is always the same.

 

[IceBear]

But then you run into the hex issues. No matter what you use (other than with a flexible ruler) you'll have to come up with some standards for dealing with oddities grids or hexes give you. I'd rather stick with grids as that's what the d20 system assumes and I use hexes for mechwarrior as that's what that system assumes.

IceBear