Monday, May 19, 2014

Inside Baseball: How acids work in game

One of the great things about hypertext versus a book is that you can link detailed information for those who really, really, really want an 'inside baseball' type information set, and like the 'shape of spells' information I provided, the following is used in the (totes non-existent) Grand Grimoire as a link in individual spell descriptions that use acid.

Acid and Alkali Information:

Acids and alkalis are some of the most dangerous substances in the game, and for the most part do the same kind of burning, disfiguring damage, often in the form of a splash from a broken vial or a magically constructed glob.

Unlike most other attacks in the game, these chemical attacks cannot be healed with regeneration abilities, only being able to be healed by a cleric's cure, the natural healing of time or by hacking off the entire area and then regenerating.

Unless otherwise stated in a description, both acidic and alkaline attacks are considered to be with a weak, not particularly persistent substance that reacts with flesh, wood, leather and similar materials to do 2d4 points of damage, or 1 point if it is a mild splash. This damage is rarely disfiguring, and if it hits water it will heat the water up a little, but do no real damage to things living in the water as long as there is 100 or more times as much water as there is substance.

Rather than have a separate category for acids and alkali, both ends of the pH spectrum are protected from by oil of acid resistance, scrolls of acid protection and the like. The substances are treated the same way except for when they encounter each other and in the amount of damage they do. They are treated as poison (more accurately poison-like compounds) that do disintegration and/or burning damage to the flesh, which can be disfiguring.

Items have saving throws against acid by name, but when they are affecting living beings, they are treated slightly differently, using the best possible category for the attack.  Acid that is suspended in the air, as well as that spit out by dragons and other creatures is saved against as a breath weapon, acid that is created by a spell is saved against by spells, acid that is hurled as a grenade-like does not get a save, but may be avoided because of a good armor class or protection. When there is doubt as to which saving throw to use against acid, the PPD (paralyzation, poison, death magic) number should be used, unless the description says otherwise.


Categories of acid:

Like poisons, acids are given a category, a number that roughly corresponds to the pH of the substance. Because the pH scale is logarithmic, and because the normal human body is slightly resistant to alkaline substances, the scale works as follows (note there is no Category 7, which would correspond roughly to water.) This table does not precisely correspond to pH, and the damage given would represent a highly purified sample, something very hard to get below 4 or above 10. Diluted samples will do a fraction of the damage, based on how dilute they are:


Acid
Category
Description
Damage
(per full dose)
Damage
(Splashing)
Damage
(Continuing)
6
Very mild acid
1
0
0
5
Common Acid
2d4
1
1d4
4
Strong Acid
10d8
2d4
2d8
3
Very Strong Acid
8d20
4d10
4d10
2
Extremely Strong Acid
10d100
2d100
2d100
1
Ancient Black Dragon Spit*
(24d4+12)X300
24d4+12
0
8
very mild alkali
1
0
1
9
common alkali
1d6
1
1d6
10
strong alkali
10d6
3d6
3d6
11
Very Strong Alkali
6d100
1d100
1d100
12
Extremely strong Alkali
6d100 X10
6d100
3d100
*Inside the dragon, prior to being released as a breath weapon that does 24d4+12 per 'hit'

A full dose of damage is taken by falling into the purified acid, being hit dead on with a pure sample thrown as a grenade-like missile, swallowing it, etc. Splashing damage occurs with a near miss as detailed on the section on grenade-like missiles. Continuing damage is damage on successive rounds with acid that is persistent. Many in-game acids are non-persistent, reacting instantly with air and vanish in one round. Continuing damage can be caused by the acid clinging to the skin of a target after s/he is removed from the acid, and lasts until the acid is removed or 2d6 rounds have elapsed. Being immersed in acid would do 'full dose' damage on each round until the target was fully dissolved. Diluted acid samples will persist less time and have no or very little continuing damage.

Reactions with Water:

Unless it is described as an acid-like substance, acids (unless they are already very dilute) react to water with a great deal of heat. Attacking a creature made of water with these substances should be saved against as disintegration or death magic (whichever is worse) and do 50% of their total full-dose damage even if just splashed upon, and that damage is in the form of boiling and steaming (the acid damage itself is mitigated by dilution). If dropped into a large body of water, 50% damage (again, from heat) occurs in a 10ft radius, 25% in the next 5ft (a total 30ft radius) and none (although the water heats up) outside a sphere that is 60ft wide.

Neutralization Reactions :

When something basic is hit with something acidic (or vice versa) the regular acid damage should occur, plus an additional 50% damage as if hitting a water-based creature with acid, and the creature will bubble as gas expands. If an inanimate object, these bubbles have a 50% chance of exploiting a critical flaw in the object and disintegrating it (perhaps even 'exploding' it, although the shrapnel won't be propelled far or hard) per round of continuing damage. The continuing damage length is halved.

Disfiguration Reactions :

Disfiguration occurs when acid interacts with the flesh and melts it, creating holes, pits and other gory-looking damage. Disfiguration is not a guarantee with most acid attacks, and indeed, the majority of acid accidents in the real world, just as with the majority of burns, are superficial or first degree burns, the acid spreading out and interacting with the first layer of skin. These are painful, but ultimately heal without scarring. Disfiguration should only be considered as a possibility if the acid attack is a called shot or does greater than one-fourth of the creature's total points in damage (unless the disfiguration is specifically noted in the attack, as with some spells.) Lasting charisma (or comeliness) damage isn't any more likely with acid scarring than with burn scarring, and like burn scarring, is healed by magical healing and time.

Saturday, March 29, 2014

Grand Grimoire Appendix on Spell Targeting, shape, etc.

Presented as a Player's Aid. Use freely, but please link back to source. Of course, The Grand Grimoire, a book containing all the mage spells in AD&D, with over 4000 spells (far more than in the Spell Compendium), totally doesn't exist and is a myth.

 Spell Targeting and Detonation Effects, Range, Area of Effect and Spell Shape.

When calculating damage of a spell, the shape, range and area of effect are incredibly important for determining who is hit and who is not. The most commonly used shapes are the sphere, ray, cube and missile. Each of these vary based upon the range of the spell.

If the range of the spell is 0, or touch, the shape of the spell must begin at the mage’s hands, unless the spell states that it comes from another part of the body or the mage is of a race that uses something other than hands (for the rest of this appendix, the word ‘hands’ will be used to describe both hands and the non-hands used in this way, including things like spells cast from wands or staves) If the range of the spell is greater than zero, and the spell is not otherwise described as originating from the mage, the spell may start anywhere within the range that the mage determines.

In the images below, a ray-shaped spell (its size is determined by the area of effect) is cast by two mages. The first image shows a range of zero:

The second image is of a ray that can be formed anywhere within a range. Note that the start of the area of effect needs to be in the range, but the end of the area of effect does not:




Unless the spell states otherwise, ray spells may be cast at any angle the mage desires. Each of the rays below represents a potential direction a ray can go. Note that some of these rays would hit the mage, the ceiling above him or whatever he is standing on. Often (but not always) the mage must be looking in the direction his ray goes.

In addition to the shape of the spell, the mage needs to understand the movement of the spell effect, if any. Rays, for example, move away from their origin (direction is represented by the arrow), usually at the speed of light. The DM generally determines that anything within sight of the ray cannot dodge once it has fired, although prescience or knowledge of the spell can allow the targets to dodge before the ray forms.

Cones are similar to rays, but occupy a larger area. Cones can have an area of effect based on an entire cone, or a partial cone. This is described in the area of effect of the spell:
 


The above represents a cone that has an area of effect of an entire cone, shown here as originating at the mage. Note that a cone-shaped spell’s area of effect is given as both a length and a width at the terminal end. The terminal end is the part furthest from the mage, the part closest to the mage is called the origin. If a cone’s area of effect is described as “10ft long and 5 ft wide” the 5ft wide describes the diameter of the circle that represents the wide end of the cone, and the 10ft long describes its length:

Sometimes a cone is described as having two ends, for example, being 10 ft long, 5ft at the end and 1ft at the beginning. Here is that cone (more accurately a partial cone):




As with a ray, a cone that does not have a range of touch or zero can start anywhere in the area of effect of the spell, as shown here (this is the partial cone from above):


 Cubes and spheres can form either around the mage or anywhere in the range of the spell. If it forms around the mage, assume the walls of the cube are equidistant from the center of the mage’s body. (or that the center of the sphere is near the center of the mage:


If the cube may be formed anywhere in the area of effect, it can be tilted in any direction the mage desires (unless the cube has weight or otherwise must have a flat edge on the floor.) If the cube spell has a range of zero, but does not form around the mage, the mage must be touching the outside edge of the cube. It is most common for the cube to form with the mage near the center of an outer wall or touching a corner. The mage often has some leeway as to angles:

A very common form of spell effect is the expanding cube or sphere, fireball being the most frequent form. This form starts as a dot—

—and then expands out equally from the initial sphere that appears (or is thrown). Here it is partially expanded. Note that the time elapsed in expansion often allows a save for half damage, as people within the area of effect dive for cover.


Finally, here is the expanding sphere fully expanded, taking up the entire area of effect.
  

In addition to the shape of the spell effect, how the mage targets it can be important. While there are dozens of targeting techniques, the most common are area effect, line of sight, touch attack and physical attack. Area effect and line of sight do not require an attack roll, and automatically hit (unless a save is allowed). A touch attack merely requires that the mage briefly touch his target, including his target’s armor, this means that the AC bonus bestowed by the armor can be ignored, but that displacement and other effects are not ignored (enemy’s DEX bonus and bonuses from shields are only allowed if he is actively avoiding the mage’s touch.) Note that held or non-resisting targets are automatically hit.
                Physical attacks are often the most risky targeting techniques for mages, because they have a low chance of hitting with physical attacks. The chance to hit is based on the target’s AC and the chance for the mage to hit as if the physical attack were a weapon he was proficient with. (A character with a THAC0 of 16 trying to hit an AC of 0 would need to roll 16 or better.)
                Understanding how a spell goes off is vital to a party’s survival. Magic Missile, for example, will swerve around a big fighter that crosses between the mage and his target, unerringly hitting the target. A fireball’s full area of effect (a sphere of 20 ft radius) cast to go off 15ft in front of the mage will easily hit the mage who cast it, and anyone between a ray of enfeeblement’s origin and its endpoint will be hit by it, regardless of whose side he is on.

Level-Based increases in Spell Power
                Many spells increase in area of effect or amount of damage as the caster’s level gets higher. Note that the caster’s level is not necessarily his actual level. For example, a bard’s “casting level” is always one level lower than his or her bard level (thus a 9th level bard casts as if 8th level,) and a swordmage’s mage-like abilities are often listed as ‘cast as if a level 12 mage,’ in which case the spell pretends the swordmage is a level 12 mage, whether his actual level exceeds that level or is beneath it. Typical Level based increases are presented below:
Type of increase
Example of listing
Example at 9th level
Example at 18th level
Additional Dice per level
1d4 per level (max 10d4)
9d4
10d4 (damage is maxed)
Base plus additional dice
100 + 1d6 per level
100+9d6
100+18d6
Additional points per level
1d6+ 1 per level*
1d6+9
1d6+18
Additional die per n level
1d6+ 1d6 per 3 levels**
4d6
7d6
Additional die per after lvl
1d6 + 1d6 per level after 10th level
1d6
9d6
Size increase-circle/sphere
radius 10ft per level
shape with radius of 90ft
shape with radius of 180ft
Size increase-cube
Cube w/10ft side per level***
Cube 90ft high, wide, long
Cube 180ft high, etc.
Size increase-cubes
One 10ft cube per level***
9 cubes, each 10ft high†
18 cubes, each 10ft high†
Size increase-Cubic Feet
100 cubic feet +10 per level
190 cubic feet
280 cubic feet
Size increase-Wall
10ft high, length 1d6+10ft per level
10ft high, 1d6+90ft long
10ft high, 1d6+180ft long
Additional number per level
Seven balls + 1 per level
16 balls
25 balls
* When written in the form of 1dN+y per level, assume that only y (not 1dN) is increasing by level unless the spell makes it explicit otherwise. For example, a spell creating one missile per level, each doing 1d6+1 damage would be written as “1 missile per level, doing 1d6+1 points of damage each” in the spell description.
** A die is added at level 3, 6, 9, 12, 15, 18, etc. See a spell’s description for how fast damage increases.
***It can be very confusing for some people to distinguish between an increase in the size of cubes and the increase in number of cubes, and can usually be demonstrated with 6 sided dice. If each die is assumed to be a 10ft cube, a 30ft cube would be made out of nine cubes, each one 10ft on a side, stacked 3 high and 3 deep-nine dice. A spell increasing by one 10ft cube per level is increasing in size slower than a spell with cubes that are growing at 10ft per level, but the character has more leeway with the position of the spell effect.
†These cubes usually must touch each other and follow logical geometry, but the player may have a lot of leeway in the shape of the effect the multiple cubes make. For example, eight 10ft cubes could make a cube 20ft high and 20ft long, a wall 10ft high and deep and 80 feet long, a shape 20ft long on one side, 40ft long on the other and 10ft high, etc.

Note that there are no partial increases. A spell that does 5 points of damage plus 10 for every two levels would do 5 at level one, 15 at level 2, 15 at level three, and 25 at level four. It would never do 10 or 20 points.