Blast Increments for Area Effects...

[Pbartender]

The new Spycraft 2.0 rulebook uses a blast increment for most "explosive" effects... I was considering using the same mechanic for spells in D20 fantasy games, notably D&D and Iron Heroes. Here's how it works:

Instead of a fixed blast radius, "explosive" (most damage-dealing bursts, emenations or spreads, for the purposes of D&D) effects have a blast increment. Within the first increment, full damage is dealt. For every blast increment after the first, damage is halved (round down). Applicable saving throws still apply.

So, for example:

Say we convert the fireball spell so that it has a blast increment of 10', instead of a fixed radius of 20'... A 6th level Wizard casts a 6d6 fireball, and rolls a total of 26 points of damage. Everyone within 10' of the point of impact would take 26 points of damage (Reflex save for half damage). Everyone between 10 and 20 feet would take 13 points (again, Reflex for half). Between 20 and 30, 6 points. Between 30 and 40, 3 points. Between 40 and 50, 1 point. Beyond 50 feet, no one takes damage.

This could not only be appplied to spells, but any other area special effects... A red dragon's cone-of-fire breath weapon, for example.

The advantage is that it would greatly extend the area of effect, with diminishing damage. The disadvantage is that it makes precision spellcasting much more difficult for many of the stereotypical artillery spells... There's a good chance that you could catch your friends in the fringes of a blast, dealing them minor amounts of collateral damage, especially if you happen to roll well for damage.

What do you guys think of the idea?

 

[Nyeshet]

Hmm, actually, I like this idea. On the other hand, many effects in the game presume certain ranges for the damages dealt. As such, it may be necessary to decrease damage increase by level somewhat. A delayed blast fireball at 20th level, for instance, is only intended to cover 20 ft, but with this system it could potentially cover 80 ft! (160, 80, 40, 20, 10, 5, 2, 1) Granted, the last fourty or so feet will not cause much damage, but imagine using such a spell upon a small army of Cold type creatures. Double damage means evens even at 50 ft the foot soldiers and grunts are experiencing 20 pts of damage. And since anything flamable that experiences at least a point of fire damage combusts this spell could cause massive damage in any wooded area. This is especially true when one considers that the perimeter is increasing swiftly (80 ft in typical casting for a 20x20 ft square; 320 ft in the current example! ).

All in all, as wonderful an idea as this is - and it is a beauty - it will require rethinking and perhaps even reworking some parts of the game to prevent the power of bursts, spreads, and similar spell effect areas.

 

[genshou]

I am a fan of this, but I have some concerns that Nyeshet has already so beautifully posted. Some work would be required to have this function with the current maximum radii.

 

[Pbartender]

A delayed blast fireball at 20th level, for instance, is only intended to cover 20 ft, but with this system it could potentially cover 80 ft! (160, 80, 40, 20, 10, 5, 2, 1) Granted, the last fourty or so feet will not cause much damage, but imagine using such a spell upon a small army of Cold type creatures. Double damage means evens even at 50 ft the foot soldiers and grunts are experiencing 20 pts of damage. And since anything flamable that experiences at least a point of fire damage combusts this spell could cause massive damage in any wooded area. This is especially true when one considers that the perimeter is increasing swiftly (80 ft in typical casting for a 20x20 ft square; 320 ft in the current example! ).

In all honesty, that is my one concern.

Having thought it over, my answer would be... You're a 20th level Wizard. Why hsouldn't your fireball be bigger and hotter than some no-talent 5th level smuck.

That, and this really changes the strategies behind using this sort of spell. Previously, a Wizard would be able to take that Delayed Blast Fireball, and deal all 160 points of damage to a group of Bad Guys standing only five or ten feet away from the Party Fighter without even singing the eybrows of your buddy... With the blast increments, you can't do that anymore. Once the Enemy closes with the Party, the Wizard will be required to deal 20, 40, or 80 points of damage to his friends, if he wants to hit the Bad Guys with 160 popints of fireball damage. That potential for collateral damage... and a rather unpredictable potential at that... should make most Wizards and Sorcerers cautious enough with these spells to balance out the increased area of effect.

But I agree... I don't think I'd muddle with the damage, but the blast increments for most spells would certainly be much smaller than the original area of effect radii.

 

[Rhun]

Having thought it over, my answer would be... You're a 20th level Wizard. Why hsouldn't your fireball be bigger and hotter than some no-talent 5th level smuck.

I actually agree with this 100%. Unfortunately, even since OD&D, things such as area of effect have never been based on the caster's level. The idea definitely has some merit, and it would definitely require a change in tactics of how spells such as fireballs are used.

 

[genshou]

I'm still not too sure about this. There are different types of grenades in existence, but just because one burns hotter than another, that doesn't mean the blast radius is necessarily that much larger. A delayed blast fireball, or a fireball by a high-level mage isn't blasting a wide area, because the intense heat is contained. Perhaps if there is a limitation on how many blast increments a spell can achieve, it won't lead to wonky results. Personally, I would use 3 maximum blast increments, with each being 1/2 of the normal spell radius. That allows for a decent range of damage values, but keeps spells from having a much wider area than they should. Also, the most central part of the effect will be where the damage is most intensified, so those toward the normal edge of the effect will only suffer half damage, and those outside the normal area of the spell but within the third blast increment will be only slightly affected at one-quarter normal damage.

 

[Pbartender]

I'm still not too sure about this. There are different types of grenades in existence, but just because one burns hotter than another, that doesn't mean the blast radius is necessarily that much larger. A delayed blast fireball, or a fireball by a high-level mage isn't blasting a wide area, because the intense heat is contained.

Eh... that's one way to explain away the current system. But that doesn't mean it HAS to be that way.

Also realize that the blast increment is also adjustable... it could be a 5 foot increment for a spell like burning hands, a 10 foot increment for a spell like fireball, and 15 feet for a spell like cone of cold, for example.

Perhaps if there is a limitation on how many blast increments a spell can achieve, it won't lead to wonky results. Personally, I would use 3 maximum blast increments, with each being 1/2 of the normal spell radius. That allows for a decent range of damage values, but keeps spells from having a much wider area than they should. Also, the most central part of the effect will be where the damage is most intensified, so those toward the normal edge of the effect will only suffer half damage, and those outside the normal area of the spell but within the third blast increment will be only slightly affected at one-quarter normal damage.

That -- or something similar -- is not a bad idea... And full/half/quarter is easy to remember and calculate. I'll have to think about that.