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Magic causing mutation, misfires, and corruption question

Started by Vic99, August 04, 2021, 06:33:14 PM

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Vic99

Working on a fantasy d20 system where magic is dangerous to use. Magic is scaled back and not the runaway train of power that is 5e D&D. Cantrips, or whatever I end up calling them, are minor like: warm a mug of liquid, stitch a tear, small zephyr to snuff out a candle, etc.

Magic mishaps for level spells are going to a misfire or cause some kind of chaotic thing to the PC or his/her environment.  I want cantrips to do this and yield a penalty for a bad roll, but not make it as harmful as a level 1 spell, etc.

What suggestions do you have for a flavorful penalty that will still make the PC use magic judiciously, but not be seriously debilitating?  Simple is ideal. Thanks.

SonTodoGato

The zephyr can backfire by tumbling objects down or triggering a gust of wind that blows things across the room causing a mess, nothing more than that. If it's lighting up a candle, it can backfire by causing a spark that could potentially cause a fire or simply leave some burnmarks on paper. Warm a mug could cause the the mug to burst and make the liquid boil (or freeze), stitching a tear can cause it to be stitched in a very untidy, messy way, etc. Just have the side effect be minor and kind of comedic and the likelihood of the cantrip backfiring be relatively small. As the level increases, it either becomes more likely or the consequence could be worse.

Apart from that, you can have magic take a toll on their sanity, health, energy, morality, etc. It does have a cost. Mad wizards, deranged warlocks, cultists, etc. are the result of being exposed to the supernatural, dealing with demons, occult forces, seeing weird things they were not meant to, etc. Perhaps you need to pay with your own blood, or you become more susceptible to the calling of the dark side, etc. Or make it addicting, Why not? The rush of feeling powerful can be addicting in and of itself.

Pat

One interesting idea in Unknown Armies is the concept of unnatural phenomena. They can happen for various reasons, but one way is by using magic. It's never certain, and how likely a phenomenon is to occur, how strong it is, and how far away it happens, are closely tied to the power of the magic. For low level spells and cantrips, they would be unusual, and happen nearby. The categories of minor effects include cold spots, minor hallucinations like hearing strange rappings or seeing a blurry presence, moisture of some kind appearing in an unusual place like the middle of a wall, technological items failing like a car not starting, or objects moving or being damaged like a mirror cracking or a ball rolling down the steps. The minor phenomena are basically poltergeist effects, but Fortean occurrences, or the transformations from Ovid's Metamorphoses, would also be a good fit, but more traditionally mythic. The idea is to make magic more a part of the world, and to have consequences. It's not predictable, but when magic is used, it often leaves behind a mark or a sign.

Another option is to adopt some ideas from UMana, a popular GURPS rules variant by S. John Ross. UMana tends to deal with catastrophic effects, but the basic concept is quite portable to more subtle magics. The core idea is that magic has a threshold. Spell points in GURPS, or it could be something like spell slots in D&D. Use magic up to that threshold, and you're fine. It goes off normal. But there's no hard limit on how much magic you can use. If you blow through all your points or slots, you can still keep on casting. But when you do so, you have to roll to see if a catastrophe happens. If you just passed the threshold, the chance of something happening isn't huge, and the result is minor. But each spell point you use beyond the threshold, or each spell slot, adds adds a modifier to the roll. So a 3d6 roll might become a 3d6+10 roll, which not only makes the check more likely, but it makes the higher items on the table more common, and it opens up a new set of catastrophes that can't be reached by as simple 3d6 roll. The more you blow out your limit, the worse the results become. Look up UMana for examples, or adopt some of the wild magic tables, if you want random stuff happening. Alternately, all the results on the table could be personal consequences. The caster might lose hp, or go temporarily insane, and the really high results that can't be reached unless you've really blown past your limits might include permanent effects, like losing a spell slot or a point of Int. The threshold diminishes over time, but it make take a while. Up to you how long.

GeekEclectic

Here are a few other ideas from other games:

In Earthdawn, casting spells without a matrix(basically a spell slot) is basically like sending a "food over here" beacon across the astral plain that hateful, hungry, and sometimes very smart creatures within a certain distance will see and likely respond to.

In Fantasy Craft(a d20 variant), there is a Corrupting Magic campaign quality you can apply that causes the caster to make a Will save every time they cast a spell, with failure resulting in a point of corruption. These points eventually disappear at the rate of 1 per scene, but if you ever get 5 points at once your character is retired as an NPC. Oh, and each point of corruption reduces your will save, making it more likely to fail later will saves against corruption.

I actually had a GM use the latter case in an interesting way. He had the Corrupting Magic quality in place, but as the game went along we learned more about why it was corrupting. It turns out there used to be a time when magic flowed freely and was safe to use, but suddenly the gods disappeared from the world, and ever since then magic hadn't worked right. Nobody currently living knows what the connection is, if any. It's a huge ??? in the setting. Eventually, we came in contact with royal scientists - the only ones legally authorized to use magic in that setting - and they had found that certain substances could leech the corruption away, keeping the caster safe, but destroying the items in the process. Basically he used it as what I thought was an interesting way to explain why magicians use reagents.

Maybe you can get some inspiration from those. Good luck.
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Eric Diaz

I'll paste a page from my Dark Fantasy Magic. Hope it's useful.

https://www.drivethrurpg.com/product/284302/Dark-Fantasy-Magic


The cost of magic
The cost of magic is one of the most important aspect of any magic system, and it is particularly important in dark fantasy games, where magic is often dangerous, corrupting or downright evil. If magic doesn't have a cost, it becomes simply a supernatural skill or superpower. Anyone with a modicum of talent will become a wizard, and magic becomes commonplace and indistinguishable from technology, with magic missiles replacing artillery and portals replacing airplanes.
In game terms, magic without a cost (other than training, etc.) creates other issues. If anyone that is sufficiently smart can become a wizard, all the best scribes, doctors, tacticians and mathematicians will be wizards. If you use charisma instead of intelligence, for example, there will be no swindlers or mundane leaders – anyone with that kind of charisma would easily become a real magician! A world so full of wizards might be very interesting, but it is not often found in the dark fantasy works that inspire this book.
The price of magic cannot be simple gold, either, or it becomes a commodity (although that might be interesting on its own). It must be something significant – maybe it requires complete devotion, madness, human sacrifice, great risks to the wizard's body or soul, or maybe it poses an existential risk to the world itself. The options are many... fortunately, we have some random tables for that! Of course, you might prefer tamer options – maybe the wizard get exhausted or temporally forgets a spell. We have tables for that too.

Costs, great and small
Here are some possibilities about the cost of casting a spell.
No cost. You can cast spells "for free". It becomes just a useful tool, or a bow with infinite arrows. While it is reasonable to think that a powerful sorcerer would be able to cast simple spells with impunity, this does not fit the dark fantasy tone we are looking for. Use it with great care, or magic will become mundane quick.
Small cost. Casting any spell has a small cost. Maybe it is spell slots, a few hit points, some gold or material components, or just a small penalty you get when casting more spells in the same day. The wizard is fine after casting a spell and, even if she cannot cast it repeatedly, she can probably do it again tomorrow.
Moderate cost. You need to spend a significant time of wealth, time or energy to cast a spell. It will affect not only your ability to perform cast more spells, but may temporarily affect your health, memory, etc., hurt your friends, or ruin the environment.
Severe cost. The cost to cast a spell is great – maybe too great. Human sacrifice is not uncommon amongst evil wizards, but human life is cheap in dark fantasy, and magic can be much more expensive. Maybe this spell requires the destruction of a rare gem or magic item; the blood of a king or the bones of a dragon; the life of a loved one; the permanent maiming of the wizard's body, mind or soul.
In general, the cost of magic will be somewhat analogous to the effects of a spell, i.e., an impressive spell will have a significant cost. Role-playing games traditionally use "spell levels" to measure the potency of a spell; when spell levels are used, the cost should be adequate to spell level, as seem below.
Notice that some costs (especially severe costs) may be relative to the magic user. For example, destroying a loved possession or a loved one is always more powerful than sacrificing a stranger. Giving away pieces of your soul becomes diminishingly effective as it becomes corrupted. And so on. 
Needless to say, the cost of magic should not be easily circumvented. If spells cost hit points, you cannot replenish these hit point by using another spell!


Risk & randomness
In addition to the expected costs, magic creates risks. The most obvious risk is that spells can go wrong – missing the target, giving false (or dubious) information, etc. There can also be a possibility of spell mishaps. Maybe the spell blows up in your face, hits an ally, or calls the attention of evil forces. While risky magic adds mystery to the system, making things too random will generate wacky results, as discussed above. To avoid this, it is useful to make the risks either fixed (for example, a failed spell will always cause exhaustion, or turn against the caster, etc.) or reasonably well suited to that one particular spell (for example, a failed fire spell will hit an ally, but a failed portal spell will send you to the wrong place).
   
Small costs – slots, points, etc.
"Ordinary" uses of magic always carry a small cost. Here are some examples; there are suited to "traditional" or "old school" games, but adaptable to other systems. You are not supposed to use all of them in the same setting, or roll randomly every time. Instead, chose one (or a few) to decide how magic works in your setting.
Although these ideas deal with game mechanics, flavor is also important. For example, spell slots will give you a "Vancian" feel, while using hit points to fuel magic will bring many other associations. This loss of hit points may represent a wizard cutting himself when casting spells, a loss of vital essence, a simple expenditure of calories, etc. In addition, it will require wizards to be more resilient than common people. Chose the explanation that best suits you game.
Here are a few alternatives to spell slots.
Hit points. You can use HP to fuel your spells. It costs 1 HP per spell level, for example; a decent die roll should reduce this cost by half (or other amount).
Magic points. You have a separate pool of magic points. It works similarly to HP, but can only be used for spells. Magic points are especially interesting because you could fill this pool with sacrifices, rituals, etc. (see moderate costs and severe costs below). Using a term such as "ka", "mana", "essence", or "souls" instead of the mundane "magic points" is a good idea to make magic sound less prosaic.
Alternatively, you can have a "resolve" or "luck" pool that can be used for magic AND other adequate activities, so even non-casters can use it.
Penalties. Every time you cast a spell, you get a penalty to cast the same spell in the same day (for example, -1 per spell level). This forces the wizard to rely on different spells instead of always using the same one.
Material components. Casting spell requires special ingredients. These might be expensive, heavy, consumable or hard to find. For example, if you require diamonds to cast spells, the cost rises with spell level (maybe exponentially so, if characters have a lot of money). Some ingredients are just impractical - even if the sacrifice of a single chicken is required, adventuring magicians will have a hard time traversing dungeons while carrying lots of live birds in their backpacks!


Moderate costs – pain and destruction
Here is a list of catastrophes that magic can cause. I use it for spell "fumbles", which means a bad die roll when attempting to cast a difficult spell. You can rule, instead, that every spell has a small chance (maybe 5% per spell level) to cause these results – even if the spell is successful. Once again, this shouldn't be easily circumvented – if you get a result that would harm you allies but you have no allies nearby, a distant loved one may get hurt.
The effects that affect the spellcaster directly are not permanent, but should last for at least a day.

d20   Cost
1   Desolation. Flora and small fauna wither and die around the spellcaster.
2   Destruction. The spellcaster's allies or friends suffer lose a total of 4 hit points per spell level.
3   Retribution. The spell turns against the caster. No save is possible.
4   Confusion. The spell gets out of control and affects another random target.
5   Inversion. The spell's effect is the opposite of the intended.
6   Oblivion. The spellcaster temporarily loses one point of Intelligence per spell level.
7   Exhaustion. The spellcaster temporarily loses one point of Constitution per spell level.
8   Exsanguination. The spellcaster loses 4 hit points per spell level.
9   Mutation. The spellcaster's body becomes warped (check the "marks of corruption" table).
10   Provocation. The spellcaster draws hostility from animals, monsters and unfriendly people.
11      Suspicion. The spellcaster becomes suspicious to everyone, even when silent.
12   Activation. Hybernating creatures awake, the half-dead rise, old spells become active.
13      Demolition. Structures fail and objects fall around the spellcaster.
14   Deprivation. The spellcaster's clothes and mundane items become useless.
15   Ruination. One magic item from the spellcaster gets destroyed.
16   Putrefaction. Food and water all around are ruined.
17   Distraction. The spellcaster is unable to cast spells for the day.
18   Stigmatization. The spellcaster gains a terrible mark on the face.
19   Convocation. A demon or other supernatural entity is summoned or takes interest on the spellcaster.
20   Debilitation. The spellcaster becomes harder to heal, resurrect, etc. (-2 to the healer per spell level).

Severe costs - sacrifice
Severe costs make powerful rituals possible. Earth-shattering spells, magic items, invocation of elder demons, permanent changes to the world... The sky is the limit (or, maybe, the Abyss). Here are some terrible costs (or severe limitations) to fuel your spells. It often requires the sacrifice of something incredibly valuable.

d10   Cost
1   Human sacrifice. Self-explanatory, but see "Costs, great and small" (above).
2   Animal sacrifice. Only powerful animals or nearly extinct species.
3   Mutilation. The spellcaster must give up a finger, eye, etc., permanently.
4   Destruction. The spell requires the destruction of an artifact or magic item.
5   The stars are right. The spell can only be cast in rare circumstances.
6   Deicide. You need a deities' blood or parts to cast the spell.
7   Time. Casting this spell requires a lot of time of work and isolation – maybe years.
8   Cataclysm. The entire place (castle, village, valley, etc.) becomes wasted and damned for centuries.
9   Damnation. Casting this spell requires a willing soul to be given away.
10   Impotence. This is the last spell the wizard will ever cast.
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Stephen Tannhauser

#6
Quote from: Vic99 on August 04, 2021, 06:33:14 PMWhat suggestions do you have for a flavorful penalty that will still make the PC use magic judiciously, but not be seriously debilitating?

How about "Wrath of the Fates"? Whenever a PC casts a spell (either at all, or with a not-quite-successful result), roll a d6 and a d10; the d10 sets a penalty to a future PC roll, while the d6 sets how far in the future it is -- i.e. if the d6 rolls 3 and the d10 rolls 7, the PC takes -7 to his third next roll.

Multiple spells set multiple penalties; if penalties accrue to the same roll, they are cumulative (e.g. if you take -4 to your fifth next roll, then take -3 to the same roll, that roll is made at -7 when you get to it). The GM tells the player the penalty when it occurs, but not before.

ETA:  For a slightly less punishing version, reduce the d10 to a d6 or d4, or set the penalty die size by the power level of the spell.
Better to keep silent and be thought a fool, than to speak and remove all doubt. -- Mark Twain

STR 8 DEX 10 CON 10 INT 11 WIS 6 CHA 3

Jam The MF

Read up on the Wild Magic Sorcerer in D&D 5E, and the Wizard Class in DCC.  Then; try to create your own thing that's just as good, or better.
Let the Dice, Decide the Outcome.  Accept the Results.

Marchand

Have you seen Call of Cthulhu d20? Any PC can use magic, but there is a cost in attribute point and sanity damage.

A sanity type mechanic might be what you are after - basically another set of damage points that the player needs to worry about.

Crypts and Things and Low Fantasy Gaming are two OSR (or OSR-adjacent) games I know of with corruption mechanics, supporting a more swords-and-sorcery feel.
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Flipped Bird

#9
Quote from: Stephen Tannhauser on August 05, 2021, 05:13:07 PM
Quote from: Vic99 on August 04, 2021, 06:33:14 PMWhat suggestions do you have for a flavorful penalty that will still make the PC use magic judiciously, but not be seriously debilitating?

How about "Wrath of the Fates"? Whenever a PC casts a spell (either at all, or with a not-quite-successful result), roll a d6 and a d10; the d10 sets a penalty to a future PC roll, while the d6 sets how far in the future it is -- i.e. if the d6 rolls 3 and the d10 rolls 7, the PC takes -7 to his third next roll.

Multiple spells set multiple penalties; if penalties accrue to the same roll, they are cumulative (e.g. if you take -4 to your fifth next roll, then take -3 to the same roll, that roll is made at -7 when you get to it). The GM tells the player the penalty when it occurs, but not before.

ETA:  For a slightly less punishing version, reduce the d10 to a d6 or d4, or set the penalty die size by the power level of the spell.

What about having the DM could roll a d10 in secret, and getting a certain number, say 6. The sixth skill or attack roll after that becomes an automatic 1. All it would take are tics on the DM's notepad.

Steven Mitchell

For a simple and usually less dangerous but far more capricious version of Stephen Tannhauser's idea:

Each caster has a Magic Corruption score (MC).  Every time a spell is cast, add the level of the spell to the MC.  When the caster attempts a saving throw, a failure works as normal.  On a successful save, the caster must then roll percentage over the MC.  Otherwise, they fail the save after all.  Once the MC causes a failed save, it resets to zero.

At some indefinite but sure point in the future, accumulated corruption will bite you.  How bad is up to fate.

Vary the numbers to taste.  To be really mean, the MC doesn't reset once it activates, but instead drops by some amount (e.g. 10 points, 1d20, etc.). To be nice, have the MC drop by some small amount when the caster fails the save outright (i.e. before the MC is even invoked).  This is more of a corruption karma mechanic, where the magic just wants you to fail later, doesn't care whether it was invoked directly or not.