Gamma Knave: Cosmetic and drawback mutations

This post is a follow-up to the "Gamma Knave" post I made recently, in which I shared a whole bunch of Gamma-World-style mutations adapted for Knave 2e. All of those mutations were cool superpowers. These are the other kinds: the ones that are harmful to you and the ones that just make you look different.

Cosmetic mutations

I think the best way to use this table is by rolling a few times, throwing out anything you don't like, and stopping when you feel you've got a look. There are no mechanical impacts from these features; balance ain't a concern here.

1	Asymmetrical	26	Stripes	51	Long, sharp nose	76	Long ears
2	Hunched	27	Textured skin	52	No nose, just nostrils	77	No external ears
3	Feathers	28	Transparent skin	53	Nose leather	78	Pointed ears
4	Fur	29	Red eyes	54	Large facial features	79	Smooth, simple ears
5	Hairless	30	Orange eyes	55	Bestial features	80	Tiny ears
6	Lumpy	31	Magenta eyes	56	Blocky features	81	Prominent browridge
7	Scales	32	Silver eyes	57	Sharp features	82	Cobra hood
8	Shaggy	33	Golden eyes	58	Smooth features	83	Dewlap
9	Red skin	34	Solid black eyes	59	Green hair	84	Long neck
10	Orange skin	35	Black scleras	60	Cyan hair	85	Long limbs
11	Yellow skin	36	No scleras	61	Blue hair	86	Stumpy limbs
12	Green skin	37	Horizontal pupils	62	Purple hair	87	Additional fingers and toes
13	Cyan skin	38	Vertical pupils	63	Magenta hair	88	Fewer fingers and toes
14	Blue skin	39	Additional eyes	64	Spiny hair	89	Large hands and feet
15	Purple skin	40	Compound eyes	65	Mane	90	Pads on palms and soles
16	Magenta skin	41	Large eyes	66	Antennae	91	Long fingers
17	White skin	42	Fangs	67	Crest	92	Webbed fingers
18	Gray skin	43	Pointed teeth	68	Head fin	93	Fins
19	Black skin	44	Tusks	69	Head tentacles	94	Vestigial tail
20	Bioluminescence	45	Long tongue	70	Antlers	95	Long tail
21	Facial markings	46	Catfish whiskers	71	Curled horns	96	Bushy tail
22	Mottled skin	47	Beak	72	Long horns	97	Pointed tail
23	Multicolored	48	Snout	73	Tiny horns	98	Vestigial wings
24	Reflective skin	49	Broad, flat nose	74	Long head	99	Strange odor
25	Speckles	50	Bulbous nose	75	Beast ears	100	Strange voice

Drawback mutations

I realized that I ought to switch to the Gamma World 5e terminology of "drawbacks" instead of the more common "defects" when I noticed how many harmful mutations were basically real issues actual humans have. I mean, I'm totally fine seeing my nearsightedness and colorblindness described as "defects", but I don't get to decide what hurts other folks.

Anyway, I did 90 beneficial mutations, and I wanted a 1d100 table, so that meant just 10 drawbacks. I think Gamma World editions usually have a harmful mutation percentage of around 15–20%, so I'm being relatively kind to my theoretical players here! But I ran some tests (in a spreadsheet, naturally) and I like the results with a 10% drawback rate a lot better than higher percentages. At 20%, I saw way too many characters with more harmful mutations than beneficial ones.

1. Allergy
2. Electrical Sensitivity
3. Hostility Field
4. Impaired Sense
5. Light Response
6. Poor Respiration
7. Prey Scent
8. Susceptibility
9. Thermal Sensitivity
10. Water Dependency

Allergy

Roll a random substance.

1	Blood	8	Gold	15	Pollen
2	Bone	9	Iron	16	Salt
3	Clay	10	Leather	17	Silver
4	Cotton	11	Oil	18	Water
5	Dust	12	Paint	19	Wood
6	Feathers	13	Paper	20	Wool
7	Fur	14	Plastic

While in contact with this material, you suffer severe irritation and are unable to take actions or move at more than half speed unless you succeed on a CON check.

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Electrical Sensitivity

You experience pain, disorientation, and minor hallucinations when exposed to electrical or magnetic fields. Handling a charged power cell or standing within 20' of a large, powered machine is enough to impose a -2 penalty on all of your checks. More severe exposure can have worse effects.

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Hostility Field [psychic]

You constantly project an irritating psychic field out to a radius of 100', causing annoyance and alienation in sapient living creatures. Reactions with affected creatures are rolled twice, keeping the worse result. Affected creatures will preferentially target you in combat. Spending a week in your company lets someone become acclimated to the field.

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Impaired Sense

Roll a random sensory impairment.

1	Anosmia. You have no sense of smell and reduced taste sensitivity.
2	Impaired Hearing. You can't hear normal conversation beyond 10' or loud sounds beyond 30'.
3	Nearsightedness. You suffer -2 on ranged attacks beyond 50' and can only perceive general movement beyond 200'.
4	No Depth Perception. You have difficulty judging the distance of objects and suffer -2 on ranged attack rolls.
5	Numbness. You don't feel pain and have very limited tactile and temperature perception. You suffer -5 on checks to perform fine manual work.
6	Total Color Blindness. You can't perceive color at all.

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Light Response

Roll to determine your relationship with light.

1–3	Dependency. You're completely blind in dim light, but intense light can't blind you. You have trouble staying conscious without light, and suffer -2 to all checks after an hour in the dark.
4–6	Sensitivity. Bright light is painful and blinding to you, but you see well in dim light. You suffer 1d6 damage if you spend a whole watch exposed to bright light.

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Poor Respiration

You can't hold your breath for more than 2 rounds. If you engage in strenuous activity (such as combat) without resting for at least 1 turn afterwards, you suffer 1d6 damage from fatigue. If you engage in strenuous activity for 1 turn, you fall unconscious.

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Prey Scent

You produce a distinct odor that attracts carnivores. When traveling, you have an additional chance each watch to have an encounter which will always be with predatory animals. Carnivores will preferentially target you in combat.

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Susceptibility

Roll to determine which danger you find difficult to resist.

1–3	Chemical. You suffer -5 on checks to resist drugs and toxins.
4–6	Psychic. You suffer -5 when defending in a psychic struggle.

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Thermal Sensitivity

Roll to determine which temperature extreme is especially dangerous for you.

1–3	Cold
4–6	Heat
7–8	Cold or heat

Any damage you suffer from extreme temperatures of that type is taken as direct damage.

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Water Dependency

You suffer 1d6 damage if you spend a whole watch without being immersed (or at least doused) in water.

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