How high can a Large(tall) creature threaten?

[Nail]

....'cause I can't find a specific reference. Do we assume that creatures are effectively "cubes", and therefore their reach extends out in a larger cubic shape?

For Example: Stone Giant with a greatclub, trying to swing at a flying wizard 35 feet up (that is, occupying the cube 7 "squares" up from the floor). Does the giant threaten the flying wizard?

 

[Primitive Screwhead]

DMG under Movement in 3 dimensions states:

Assume the creature is as tall as thier face and can reach upwards the distance equal to thier normal reach..

or something akin to that.. too little bandwidth to hit the SRD right now.

As such a Large creature, face of 10' and a reach of 15' can hit a character 25 feet up.

With the (tall) connotation.. house rule territory. I would go with 1.5 of Face, meaning threaten up to 30' from the ground. Of course a 5' Hop gets the flying mage within range for one smack {jump check DC 10 IIRC}

 

[the Jester]

I'd rule that the giant can reach (height + reach) feet in the air. Height often fails to correspond meaningfully with space.

 

[Infiniti2000]

I'd rule that the giant can reach (height + reach) feet in the air. Height often fails to correspond meaningfully with space.

I agree. This means that a stone giant can reach 22ft into the air. If we follow D&D truncation rules, then he can only attack up to 20ft (i.e. creatures flying below 20ft, not at 20ft). If you don't want to just discard that 2ft, then you can let him attack at the 20ft level as well, perhaps applying a circumstance penalty at that point (per the rules and DM fiat on circumstance penalties).

But, keep in mind that you need to also applying the squeezing rules on creatures based on height. The same stone giant would be squeezing (perhaps) while walking down a 10ft-high corridor. This vertical squeezing really becomes apparent when you are talking about big elementals, which get to be really tall.

 

[Nail]

Isn't there RAW guidance somewhere on how "height" of a creature interacts with Space?

As an easy example: A Frost giant is size Large (10'), yet has a height of 15'. Total reach up equals:

• 20 ft (10ft space + 10 ft reach), or
• 25ft (15ft height + 10 foot reach).

I could see an explanation for option #1. After all "reach" is as much a combat abstraction as "space", and insisting on adding an abstract number to a actual (height) number..........

 

[Infiniti2000]

Isn't there RAW guidance somewhere on how "height" of a creature interacts with Space?

Not to my recollection. But, then again, I'm getting old.

I could see an explanation for option #1. After all "reach" is as much a combat abstraction as "space", and insisting on adding an abstract number to a actual (height) number..........

Obviously, I go with #2. If the creature's height is specified, it should probably be used. The creature's length and/or width is not as important (e.g. a purple worm fits within a 20x20 Space despite being 80ft long) but even in some cases, that doesn't make sense (a roc, no matter how you slice it, fills up way more squares than its Space -- can you say 80ft wingspan?). So, there are problems with Space in d20.

However, if you use Space for height, you might get cases where a creature cannot even attack in a 'square' (I call 'em voxels) below its actual Height. The purple worm is one arguable example (if you accept that a snake-like creature can extend half its height up), but a clearer example is the Elder Fire Elemental. It as a height of 40ft, but a Space of 15 and a Reach of 15. Per your rule #1, it could only Reach 30ft high, 10ft below the top of the creature. So, you could fly through (or near) the top of the creature and it could not even attack you! IMO, this is strong evidence to use Rule #2.