Overkill and collateral damage on the environment

[EoNhOeKnOwS]

Hello everyone

So my caster is able to cast fireball and he's able to do a flat 162 fire dmg from the spell.

We happen to be in a dense forest with undergrowth and 10x10 trees dotting the scape.

While I was focusing on trying to get rid of as many enemies so that we weren't out numbered I obviously neglected to think of the devastation that was soon to occur, one of the enemies caught in the blast was a greater air elemental who turned into a whirlwind because it lived with 16 hp...

To say the least, there were some spectacular visual effects from overkill, which disintegrated trees, trunk and all, as well as catch all the undergrowth on fire AND the elemental turned into a whirling vortex of fiery doom ...

How fast would the fire spread (the fire carried by the elemental as well as left over fire from the undergrowth), do rocks/boulders suffer dmg from fireball? Fireball says that there's no pressure from the blast, so nothing gets sort of pushed away but if you detonate a fireball that deals that much dmg 5 ft above a target I feel the target would either be disintegrated to ash and leave a crater behind ...

What're your alls thoughts on how to handle a situation like this, mayhaps I didn't elaborate enough but let me know if it's not clear enough

Thanks!

[Malimar]

Well, the relevant page is here (http://www.d20srd.org/srd/exploration.htm) (or here (http://www.d20pfsrd.com/gamemastering/exploration-movement#TOC-Breaking-and-Entering) for Pathfinder, I think all the numbers are the same).

With a fireball dealing 162 fire damage:

All non-magical, unattended objects in the area automatically fail their Reflex saves and take full damage.

For boulders, "Electricity and fire attacks deal half damage to most objects; divide the damage dealt by 2 before applying the hardness" definitely applies, stone has 8 hardness and 15 hp/inch of thickness. Rocks bigger than 5ish inches in diameter are only scorched or have their surfaces glassed; rocks smaller than that may melt or explode.

For trees, I probably wouldn't halve the fire damage. Wood has hardness 5 and 10 hp/inch of thickness. Saplings and small trees less than 15 inches in diameter explode; the 10'x10' tree trunks are only scorched.

For the underbrush and leaves, I'd probably go with the stats for paper/cloth (or possibly leather/hide or possibly wood) and possibly even apply "Certain attacks are especially successful against some objects. In such cases, attacks deal double their normal damage and may ignore the object’s hardness"; paper/cloth has hardness 0 and 2 hp/inch of thickness, but even if we're using wood stats, all the underbrush within range is annihilated/disintegrated by this fireball because very little underbrush is more than an inch or two thick.

Anything flammable that isn't outright annihilated catches fire, as per "The fireball sets fire to combustibles and damages objects in the area." I usually have nonmagical fire advance through flammable material about 1 square per round, but that has no basis in the rules.

[Jack_Simth]

Well, most of the area you just hit will now be a blackened waste. However: Depending on the recent weather and your DM, you may have just started a forest (http://www.d20srd.org/srd/wilderness.htm#forestFiresCr6) fire (http://www.d20pfsrd.com/gamemastering/environment/wilderness#TOC-Forest-Fire) that you'll now want to escape.

[EoNhOeKnOwS]

Great! Thank you guys, this is wonderful input. It was real late, we wanted to end the session so we didn't put a lot of on the spot thought about the big picture, I feel that instances like this are gonna be a common occurrence and should be well informed for when it does happen again.

My real curiosity is the "overkill" factor, for example, one of the enemies caught in the blast was a frost giant which took 243 dmg. Would taking this sort of damage (way above their max hp) cause their bodies to explode or melt or become ash? What about being struck by lightning with the same damage, or frost or sonic, or anything. I mean I suppose frost would just be the quintessential flash frosted ice cube, what does everyone else think?

Or is it simply DM discretion to have a body explode or simply keel over?

EDIT: would an energy substituted fireball to ice (for example) have a frost effect left over?

[Bakkan]

This sort of choice is left to the DM and the players. The rules say nothing about there being a difference in a 2 hp commoner dying from a 12 damage greatsword swing or a 1200 damage metamagic'ed orb of fire. It's a lot of fun to describe the carnage from overkill, but everyone should remember that some of these descriptions would have actual mechanical effects. For instance, if the commoner above is vaporized by the spell, he is no longer eligible to be brought back to life by certain resurrection spells.

[Lormador]

Prepare for various druids to have a problem with what you're doing, some of whom might be willing to negotiate peacefully and others of whom will think more along the lines of an ambush.

[icefractal]

The rule of thumb I use for damage beyond dead is:
-(HP+10): Reduced to pieces, beyond Raise Dead but not beyond Resurrection.
-(2x HP+10): Totally annihilated.

Where HP is the creature's full HP. That's only for attacks where it makes sense - an arrow is not going to reduce someone to ash or even chunks, they'll just be very dead.