Magical Mutations [Horror/Thaumatology]

[AlexanderHowl]

I would like to avoid having creatures that are totally dysfunctional.

[Inky]

“We’ve strayed into a zone with a high magical index,” he said. “Don’t ask me how. Once upon a time a really powerful magic field must have been generated here, and we’re feeling the after-effects.”

“Precisely,” said a passing bush.

Hrun’s head jerked down. “You mean this is one of those places?” he asked. “Let’s get out of here!”

“Right,” agreed Rincewind. “If we retrace our steps we might make it. We can stop every mile or so and toss a coin.”

\\\\\\\\\\\\\

[Jinumon]

Originally Posted by AlexanderHowl

I would like to avoid having creatures that are totally dysfunctional.

I think this depends simply on what advantages and disadvantages you allow as a result of your mutations. Personally, I'm generally against the idea of things restricted only by "chosen by the GM" as they, like all things dependent solely on the whims of an individual or individuals, are inconsistent. You might allow something one day that you disallowed a previous day because your mood or perspective changed, or because someone cajoled you in the right way.

I think a better solution is to create a list of acceptable traits and modifiers and to say that, unless there is a very specific need for something outside that list, that everything else is disallowed. An existing system that does this the random side-effects present in the Mutations chapter in GURPS After the End 1: Wastelanders, pp. 25-26. Here you have a relatively short list of disadvantages that, while impactful, likely won't destroy a character concept outright. Similarly, you can create a list of acceptable traits and modifiers which you have actively considered and can be relatively sure won't result in a completely dysfunctional creature.

While the idea of going through every trait and modifier can seem daunting, it really isn't as big of an undertaking as it seems. The entirety of the Advantages and Disadvantages chapters in the GURPS Basic Set: Characters, GURPS Power-Ups 4: Enhancements, and GURPS Power-Ups 8: Limitations all total less than 200 pages of material, which can likely be skimmed and plucked for appropriate information in an afternoon or three. Add another afternoon to construct some random trait tables and you've got a solid working framework for quick creation of aberrant flora and fauna.

On an unrelated note, again regarding the rate at which traits are accumulated, there is an established precedent for acquiring 1-2 CP of positive traits in as little as 50 days completely passively (see Learnable Advantages: Cultural Familiarity and Languages, GURPS Basic Set, p. 294). This could be used as a baseline (Normal Mana) or as the most extreme case (Very High Mana) in your world. While the rate at which traits are accumulated is ultimately up to you as the GM, I generally try to base my homebrew systems on existing examples, and so figured I'd point this out to you.

Jinumon

[Flyndaran]

Way back, I started to create a setting based around that idea. Humanity comes from one no mana region about the size of Oregon. They just reached a low level super science tech level with dirigibles and decided to launch an expedition over the mutated lands of high mana to find any habitable regions.

They know of fey and beasts that prowl the low mana regions. The beautiful elves all just have instinctive illusions while the fowl goblins are the same people lacking such magics. At best, they are "weird" from the warping energies.

A framework to nail down the specifics of what happens to any "heroes" who stray too far into and stay too long in such regions sounds interesting.

[Flyndaran]

Originally Posted by Jinumon

I think this depends simply on what advantages and disadvantages you allow as a result of your mutations. Personally, I'm generally against the idea of things restricted only by "chosen by the GM" as they, like all things dependent solely on the whims of an individual or individuals, are inconsistent. You might allow something one day that you disallowed a previous day because your mood or perspective changed, or because someone cajoled you in the right way.
...

Jinumon

I think a good idea might to split the difference with mutations tending toward making personality traits more overt and physical. The face any problem with a hammer guy might go the big strong ugly classic ogre route. The rogue type could develop magics that make them less noticeable for good and bad.

[AlexanderHowl]

Well, that assumes 8 hours of self-study for 50 days, which ends up being 7 CP of changes every year, which would be fine for very high mana. A simplified version might keep the interval and just roll 4d for positive traits and 2d for negative traits, giving an average of a net 7 CP every interval. A 1d roll for each (positive and negative) could determine allocation:

1: supernatural mental
2: exotic mental
3: mundane mental
4: mundane physical
5: exotic physical
6: supernatural physical

For the mundane categories, you could roll another 1d for further allocation:

1-2: attributes
3-4: secondary characteristics
5-6: advantages/perks

[Jinumon]

Originally Posted by AlexanderHowl

Well, that assumes 8 hours of self-study for 50 days, which ends up being 7 CP of changes every year

That's the case for most forms of self-study. The rules for learning Cultural Familiarity and Language specifically state that the hours per day toward those traits are accrued "no matter what else you are doing (even studying skills - an exception to the "one skill at a time" rule)."

Jinumon

Note: I'm directly quoting less than 3 lines of text from a book during the "3-column" era of publication. I know direct quotes are frowned upon and I hope this is a small/inconsequential enough passage to avoid getting me in trouble. If it is a problem please just let me know and I'll delete it myself.

[Flyndaran]

I just realized the weird mutations is very similar to the Piers Anthony novel, Mute. In it, gametes exposed to space radiation result in offspring having mutations, usually bad, but sometimes psychic. I mean really weird, because two characters are a telepathic weasel and a clairvoyant crab.
The protagonist has a minor physical issue but also unconsciously makes everyone forget his existence.