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View Full Version : D&D 3.x Other Deep Cold Ruleset - Frostfell is for babies!



Aldurin
2014-08-31, 09:53 PM
This is an expansion of the temperature bands listed in Frostburn, since my setting involves a colder Frostfell (and probably space stuff) so I need mechanics for all the way to when matter hovers right above absolute zero. These new bands are called barriers, in reference to the fact that new obstacles appear in traversing environments at these temperatures.



Unearthly Cold
-50° F to -100°F


Ungodly Cold
-100°F to -200°F


Organic Barrier
-200°F to -300°F


Breathing Barrier
-300° F to -320° F


Nitrogen Barrier
-320° F to -425° F


Hydrogen Barrier
-425°F to -450°F


Tranquility Barrier
-450°F to -459.66°F



Note: Any typeless damage listed immediately inflicts frostbite and hypothermia.

Ungodly Cold:
Full Protection Level: 5+
Partial Protection Levels: 4-3

Anyone in this environment can end up freezing solid on a moments' notice, and fights are often decided by who can damage their opponent's cold protection first. Unprotected characters take 1d6 cold damage and 1d6 nonlethal damage per round (no save). Partially protected characters take damage per minute instead of per round. In this environment, even magic begins to yield to the cold. All spells and powers without the cold subtype have a 5% failure chance, rolled separately from normal arcane spell failure and similar interference.

Organic Barrier:
Full Protection Level: 6+
Partial Protection Levels: 5

Nothing is safe at this temperature, and is listed as the point where no organic creature can survive without massive preparation, both mundane and magical. Even cold subtype creatures can be found frozen, monuments to the dangers of the region. Unprotected creatures take 2d6 cold damage and 1d6 typeless damage per round. Partially protected creatures take 1d6 cold damage and 1d6 nonlethal damage per round. Non-cold spell and power failure chance increases to 10%.

Breathing Barrier:
Full Protection Level: 7+ (airtight)
Partial Protection Levels: 5-6, 7 (not-airtight)

At this point oxygen liquefies, leaving an almost pure-nitrogen atmosphere that's unsafe to breathe above, and a sea of liquid oxygen nearly impossible to traverse below.
Upper Layer (Nitrogen Atmosphere): Unprotected creatures in the upper layer take 4d6 cold damage and 2d6 typeless damage per round. Partially protected characters take 2d6 cold damage and 1d6 typless damage per round instead.
Lower Layer (Oxygen Sea): Unprotected creatures in the lower layer take 6d6 cold damage and 4d6 typeless damage per round. Partially protected characters take 4d6 cold damage and 2d6 typeless damage per round instead. The DC of any attempted swim check increases by 10.
Both Layers: Non-cold spell and power failure increases to 20%. Cold subtype powers and spells have a 5% chance of failure.

Nitrogen Barrier:
Full Protection Level: 7+ (airtight)
Partial Protection Levels: 6, 7 (not-airtight)

Even Nitrogen liquefies, forming a layer of liquid nitrogen over the liquid oxygen layer. The atmosphere is now entirely helium, with hydrogen farther up.
Upper Layer (Helium Atmosphere): Unprotected creatures take 6d6 cold damage and 3d6 typeless damage per round. Partially protected creatures take 4d6 cold damage and 2d6 typeless damage per round. Listen check DCs increase by 10, but penalties for distance only apply for every 30 feet of distance instead of every 10 feet.
Lower Layer (Nitrogen Sea): Same as Oxygen Sea, except swim check DCs increase by 15 instead of 10. Note that deeper into this barrier, the nitrogen will eventually freeze, leaving no choice but to continue through the upper layer.
Both Layers: Non-cold spell and power failure increases to 25%. Cold subtype powers and spells have a 10% chance of failure.

Hydrogen Barrier:
Full Protection Level: 8+ (airtight)
Partial Protection Levels: 6-7 (airtight)

The only gas to remain is helium, and the only liquid hydrogen. What could you possibly gain by going this far into the cold?
Upper Layer (Helium Atmosphere): As the Nitrogen Barrier's upper layer, except all damage die increase by 2.
Lower Layer (Hydrogen Sea): As Nitrogen Sea, except both damage die increase by 4, and swim check DCs increase by 25 instead of 15. As with the Nitrogen Sea, this layer eventually solidifies at the colder end of this barrier.

Tranquility Barrier:
Full Protection Level: 10+ (airtight)
Partial Protection Levels: 8-9 (airtight)

Helium liquefies at this point, creating an empty atmosphere and a sea of Helium. If this barrier goes far enough, the helium sea will freeze as well, leaving you on the edge of perfect cold. Silent, serene, beautiful and ready to freeze your blood vessels fast enough to shatter them the moment you let your guard down.
Upper Layer (Empty Space): Unprotected living creatures die, no save. Unprotected non-living creatures take 10d6 cold damage and 8d6 typeless damage per round. Partially protected creatures take 8d6 cold damage and 6d6 typeless damage per round. Listen check DCs increase by 20, and can only be made for sounds traveling through a solid object that the listener is in contact with. Wing-based flight is non-functional here, as there is no atmosphere to push against to gain thrust.
Lower Layer (Helium Sea): As Hydrogen Sea, except both damage die increase by 6 and swim check DCs increase by 40 instead of 25. Again, this layer eventually freezes deeper into the barrier.
Both Layers: Non-cold spell and power failure chance increases to 50%. Cold subtype powers and spells have 20% failure chance.

Void of Space (Alternate application of Tranquility Barrier):
Full Cold Protection Level: 10+ (airtight)
Partial Cold Protection Levels: 8-9 (airtight)
Full Heat Protection Level: 4
Partial Heat Protection Levels: 2-3

Space is cold, empty and fraught with solar radiation. It's no wonder people prefer to explore the planes instead.
Empty Space: Unprotected living creatures die, no save. Unprotected non-living creatures take 10d6 cold damage and 8d6 typeless damage per round. Partially protected creatures take 8d6 cold damage and 6d6 typeless damage per round. Listen check DCs increase by 20, and can only be made for sounds traveling through a solid object that the listener is in contact with. Wing-based flight is non-functional here, as there is no atmosphere to push against to gain thrust. Additionally, creatures without proper heat protection also take damage as if they are subject to Unearthly Heat (Sandstorm p.12) if they are in line-of-effect to the sun.

Airtight protection:

While D&D 3.5e doesn't seem to have any spell or equipment that provides practical airtight protection for an expedition, it should still be a critical part of your party's preparations. You can easily whip up a few simple equipment and spell concepts to fit the role, and adapt as needed. Do keep in mind whether you want combat in areas requiring this protection to be a risk about having their protection pierced. You'll want to emphasize physical protection more if you want air seal breaches to be a prominent hazard, or spell-based protection if you'd rather keep that risk present in traveling more than in combat.

Adapting these rules (weather, civilization, etc.):

This level of cold is a very fuzzy area for fantasy, and in some ways for science, too. What your party encounters within each barrier is up to you, though there are some good ones to keep in mind. Weather will likely work differently, as water will have frozen much farther back and may not even serve as a proper cloud presence, so there may not even be weather (though you could create new forms of weather based on evaporation cycles from each of the gases as they reach their liquefying point). Ruins and evidence of civilization may need to be sparse and even more mysterious, unless you decide that a shift in the material plane caused this region of extreme cold to slowly move into this area in the past. Encounters should probably be rare, and either be by extremely tough cold creatures (modifying existing ones or making new, alien ones works) or other people who have managed to journey into the same area with similar equipment. In the end, how you make use of this ruleset and the areas it creates are up to you, and you should change and adapt it to suit your campaign or setting the way you want.

qazzquimby
2014-08-31, 11:49 PM
If you don't mind using a calculator, I have rules (http://www.giantitp.com/forums/showsinglepost.php?p=16661297&postcount=121) for this and several other things that match raw for the most part and rl when raw gets sketchy.
I don't have useful feedback for you because it all looks pretty good.

Aldurin
2014-09-01, 10:03 PM
If you don't mind using a calculator, I have rules (http://www.giantitp.com/forums/showsinglepost.php?p=16661297&postcount=121) for this and several other things that match raw for the most part and rl when raw gets sketchy.
I don't have useful feedback for you because it all looks pretty good.

Thanks! I was expecting one of the early responses to be "this is an offense to science" because of how much I generalized the concepts, but it's good to know I'm on the mark for a crunch-lite version.

Tanuki Tales
2014-09-01, 11:26 PM
How would these rules interact with...say...Atropus, who is an undead moon? Would divine/semi-divine creatures just get flat immunity to temperature effects?

Edit:

And while talking about Atropus, it has no atmosphere but is populated by thriving populations of undead. So I guess using these rules, you'd just have Atropus extend some kind of protection to all undead around it.

Aldurin
2014-09-01, 11:41 PM
How would these rules interact with...say...Atropus, who is an undead moon? Would divine/semi-divine creatures just get flat immunity to temperature effects?

You could deem that Atropus and the substances that compose it are magically immune to these rules, given its origins and power. If you don't want the surface to count as being constantly in a Tranquility Barrier, you could rule that Atropus has its own atmosphere (optional on whether it's safe to breathe) leftover from worlds it has devoured or produced by vents on its surface, and even rule a natural amount of heat to push it up to a warmer temperature band.

Of course the Elder Evils supplement has its own far simpler rules for handling the fact that it's in the void of space (without the cold damage of this ruleset, of course).

Since I'm running with a modified encounter of Atropus in my campaign, but providing multiple means of space survival, I'll probably be counting the surface as part of the Void of Space variant of the Tranquility Barrier, ruling that all of the natural encounters on Atropus automatically count as protected.

RedWarlock
2014-09-02, 10:44 AM
Space itself isn't actually cold, since vacuum is an insulator, and while heat can dissipate through radiation, it's a very slow process. (In hard SF, waste heat is a bigger issue than the 'cold of space'.)

A object in space, sharing our orbit from the sun, is actually vey much vulnerable to heat and radiation damage, since the sun's light transmits energy directly, whereas normally atmosphere and the earth's protective field guard us from sunlight's heat and radiation.

So for Atropus and the undead on its surface, the lack of atmosphere doesn't generate overwhelming cold for its inhabitants, but they might suffer damage from the sun when they draw near enough to the habitable zone of a solar system.