Notes
This work is incomplete. It still needs to be drawn together and form a consistant whole. I plan on having two systems for Radiation Damage in my D&D 5e Gamma World system. The first is a realisitic system that will be used for dramatic purposes. This will be a system that will model the idea of someone who is so radiated that they are going to die, but it will take them weeks or months to do so. This will give the player the option of finding a cure with some sort of Ancient Tech or revenge a wrong before dying. The other system will mirror the radiation systems found in 1st and 2nd editions of Gamma World. This system is not complete yet, as the math is still being done. This second system will basically set a CON Save vs a DC that is based on the Radiation Intensity plus any modifiers based on armor or whatnot and give you an outcome that can either be mitigated by damage, mutation, or exhaustion effects. I also plan on having a new damage type that will track to radiation damage in the realistic / dramatic system. Radiation Damage effects will be able to be mitigated by Ancient Tech Medicine whcih will either repair your radiation stat or your remove various effects and negative bonuses to CON rolls.
Nukes and Radiation in Gamma World
Insert summary Here
Radiation Damage
Insert Summary Here
A New Stat
Every character in Gamma World has a new stat that accounts for the amount of radiation damage they can take. This stat is based on a creatures constitution and increases or decreases as that creatures constitution increases or decreases. This new stat is called Rads. To calculate the number of rads a creature has take it’s CON and multiply it by 100. For example if a character has a constitution of 10 then they have a Rads of 1000. Once you have this value you will multiply it by a modifier as found in the table below based on the characters size.
Size |
Multiplier |
Tiny |
x1/4 |
Small |
x1/2 |
Normal |
none |
Large |
x2 |
Huge |
x3 |
Gargantuan |
x4 |
Damage to your Rads
You reduce the amount of Rads you have when you encounter radiation in Gamma World. This radiation might be in the form of fallout from the bombs the ancients dropped or from creatures in Gamma World. What makes Radiation damage so dangerous is that only the Ancients knew how to cure radiation damage.
Nauseaed:
- A nauseated creature can’t take actions or reactions.
- A nauseated creature has disadvantage on attack rolls and ability checks.
- A nauseated creature automatically fails all saving throws except those made to shaking off these effects.
Anorexia
- An Anorexiad character must make a Wisdom check (DC?) every time they try to eat. When they fail, they are unable to eat. On a sucess the character consumes half rations.
- An anorexiad character follows normal 5e Rules for lack of nutrition / water.
Vomiting
- A vomiting character must make a Con Check (DC?)1D4 minutes after they finish eating. On a fail, they vomit up their food and water and recieve no nutritional value from the food and only half rations value for the water. If the character was already drinking 1/2 rations, they get no nutritional value.
- A Vomiting character follows normal 5e rules for lack of nutrition / water.
Diarrhea
- A character with Diarrhea must make a Con Check (DC?) 1D4x10 minutes after they finish eating. On a fail, they pass their food and water out of their body and recieve no nutritional value from the food. This check is in addition to a check for a character who is Vomiting. If a character has failed their Con Check for Vomiting, they will not need to roll for Diarrhea.
- A character with Diarrea follows normal 5e rules for lack of nutrition / water.
Watery Diarrhea
- A character with Diarrhea must make a Con Check (DC?) 1D4x10 minutes after they finish eating. On a fail, they pass their food and water out of their body and recieve no nutritional value from the food and the food. This check is in addition to a check for a character who is Vomiting. If a character has failed their Con Check for Vomiting, they will not need to roll for Diarrhea.
- A character with Diarrea follows normal 5e rules for lack of nutrition / water.
Bleeding
- A character who is bleeding from ionization damage must make a Con Check (DC?) every hour or lose 1 hitpoint.
- or A character who is bleeding from ionization damage must make a Con Check (DC?) every day or lose 3D6. On a sucessful roll, lose half that.
Convultions
- A Character with Convultions must make a Con Check (DC?) every hour. On a fail the creature can’t take actions or reactions and they take 1d4-2 damage if they are restrained carefully, otherwise they take 1d4 damage.
Damage from Radiation based on the Center for Desiese Control studies on Ionization Damage from Radiation.
Prodromal Stage
Syndrome |
Low Dose |
High Dose |
Onset |
Length |
Symptoms |
Hematopoietic (Bone Marrow) |
30 |
70 |
7D6-6 Hours |
1D12 days |
Anorexia, Nausea, and Vomiting |
Gastrointestinal (GI) |
600 |
1000 |
1d4 hours |
1d4*10+1d8 hours |
Anorexia, Nausea, Vomiting, Diarrhea, one level of exhaustion |
Cardiovascular (CV) |
2000 |
5000 |
1d4 minutes |
1d4 hours |
Vomiting, watery diarrhea |
Central Nervous System (CNS) |
2000 |
5000 |
1d4 minutes |
1d4 hours |
Nausea, Vomiting, Unconscious, |
Latent Stage
Syndrome |
Low Dose |
High Dose |
Length |
Symptoms |
Hematopoietic (Bone Marrow) |
30 |
70 |
1d6 weeks |
Suffers from one level of exhaustion |
Gastrointestinal (GI) |
600 |
1000 |
1d8 days |
One Level of Exhaustion |
Cardiovascular (CV) |
2000 |
5000 |
1d4 hours |
One Level of Exhaustion |
Central Nervous System (CNS) |
2000 |
5000 |
1d4 hours |
One Level of Exhaustion |
Manifest Illness Stage
Syndrome |
Low Dose |
High Dose |
Length |
Symptoms |
Hematopoietic (Bone Marrow) |
30 |
70 |
1d3 + 1 months |
Anorexia and One Level of Exhaustion. |
Gastrointestinal (GI) |
600 |
1000 |
1d4/2 |
Anorexia, Diarrhea, One Level of exhaustion |
Cardiovascular (CV) |
2000 |
5000 |
1d4 days |
Watery diarrhea, Convulsions, Max level of Exhaustion |
Central Nervous System (CNS) |
2000 |
5000 |
1d4 days |
Watery diarrhea, Convulsions, Max level of Exhaustion |
Recovery Illness Stage
Syndrome |
Low Dose |
High Dose |
Recovery Time |
Symptoms until Recovery |
Hematopoietic (Bone Marrow) |
30 |
70 |
1d100 weeks |
Suffers from one level of exhaustion |
Gastrointestinal (GI) |
600 |
1000 |
Death |
Generally there is no recover stage |
Cardiovascular (CV) |
2000 |
5000 |
Death |
Generally there is no recover stage |
Central Nervous System (CNS) |
2000 |
5000 |
Death |
Generally there is no recover stage |
Damage from a Nuke
The following information is based on real world physics for weapons and the amount of damage structures can take in Gamma World. Ranges are listed in Feet.
Blast Damage (Thunder, Bludgeoning, and Force Damage)
Description |
PSI |
Damage |
10000 psi / surface (destruction of even very hardened silos) |
10000 |
190D100 |
1000 psi / surface (hardened silos destroyed/damaged) |
1000 |
10D100 |
600 psi / surface (destruction of highways and airfields) |
600 |
36D20 |
200 psi / surface (underground water and gas lines destroyed) |
200 |
20D20 |
20 psi / surface (severe to complete damage to most buildings) |
20 |
8D12 |
5 psi / surface (destruction of wooden buildings, heavy damage to brick/steel buildings) |
5 |
5D12 |
1 psi / surface (broken windows, light damage) |
1 |
1d4-2 |
REMs (Average Human has 1000 REM for their lifetime) |
|
|
Blast Damage Range in Feet
Description |
20t |
1kt |
10kt |
20kt |
1 MT |
10 MT |
20 MT |
10000 psi / surface (destruction of even very hardened silos) |
|
70 |
150 |
190 |
690 |
1,490 |
1,870 |
1000 psi / surface (hardened silos destroyed/damaged) |
|
150 |
330 |
420 |
1,540 |
3,326 |
4,171 |
600 psi / surface (destruction of highways and airfields) |
50 |
190 |
400 |
500 |
1,850 |
4,013 |
5,016 |
200 psi / surface (underground water and gas lines destroyed) |
70 |
260 |
570 |
720 |
2,640 |
5,702 |
7,181 |
20 psi / surface (severe to complete damage to most buildings) |
190 |
710 |
1,540 |
1,940 |
7,128 |
15,365 |
19,378 |
5 psi / surface (destruction of wooden buildings, heavy damage to brick/steel buildings) |
410 |
1,500 |
3,221 |
4,066 |
14,995 |
32,366 |
40,762 |
1 psi / surface (broken windows, light damage) |
1,050 |
3,854 |
8,342 |
10,454 |
38,597 |
83,424 |
104,544 |
Radiation Damage (Necrotic)
Description |
Damage |
500 REM (50-90% Mortality without medical Care) |
See Table Above |
600 REM (80% Mortality Rate with Medical Care) |
See Table Above |
1000 REM (95% Mortality Rate with Medical Care) |
See Table Above |
5000 REM (100% Mortality) |
See Table Above |
Radiation Damage Range
Description |
20t |
1kt |
10kt |
20kt |
1 MT |
10 MT |
20 MT |
100 REMs (Sickness, increased lifetime cancer risks) |
2,060 |
3,643 |
5,174 |
5,702 |
9,451 |
12,355 |
13,886 |
500 REM (50-90% Mortality without medical Care) |
1,400 |
2,746 |
4,118 |
4,594 |
8,184 |
11,088 |
12,672 |
600 REM (80% Mortality Rate with Medical Care) |
1,340 |
2,640 |
4,013 |
4,488 |
8,078 |
10,930 |
12,514 |
1000 REM (95% Mortality Rate with Medical Care) |
1,170 |
2,390 |
3,696 |
4,171 |
7,656 |
10,507 |
12,091 |
5000 REM (100% Mortality) |
720 |
1,660 |
2,746 |
3,168 |
6,389 |
9,134 |
10,718 |
Radiation Damage (Fire)
Description |
Damage |
Dry wood usually burns (35 cal/cm²) |
10d12 |
Third degree burns (100% probability) |
4d12 |
Third degree burns (50% probability) |
4d12 |
Second degree burns (50% probability) |
2d12 |
First degree burns (50% probability) |
1d12 |
Radiation Damage Range
Description |
20t |
1kt |
10kt |
20kt |
1 MT |
10 MT |
20 MT |
Skin burns (Fire Damage) |
|
|
|
|
|
|
|
Dry wood usually burns (35 cal/cm²) |
|
740 |
2,320 |
3,221 |
20,803 |
59,664 |
81,840 |
Third degree burns (100% probability) |
450 |
1,650 |
4,594 |
6,283 |
35,059 |
93,984 |
126,192 |
Third degree burns (50% probability) |
480 |
1,780 |
4,963 |
6,758 |
37,594 |
100,848 |
134,640 |
Second degree burns (50% probability) |
590 |
2,170 |
6,072 |
8,290 |
46,042 |
123,024 |
164,208 |
First degree burns (50% probability) |
840 |
3,115 |
8,501 |
11,563 |
62,304 |
163,680 |
216,480 |
Minimum radius for 100% probability of no harm |
1,080 |
3,960 |
10,930 |
14,784 |
78,672 |
203,808 |
271,392 |
Visible Fireball and Blast
Description |
20t |
1kt |
10kt |
20kt |
1 MT |
10 MT |
20 MT |
Fireball Radius |
50 |
260 |
650 |
860 |
4,118 |
10,349 |
13,675 |
Airblast Radius |
50 |
3,854 |
8,342 |
10,454 |
38,597 |
83,424 |
104,544 |
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