Unstable magic in a campaign setting

[Rusvul]

I will soon be running a 5e game set several thousand years after a sort of magical overload. This overload changed the plane significantly, causing a 'fall of Rome' type situation, and gradually terraforming the plane into a swamp... flooding the Underdark in the process. The Drow emerged and pretty much conquered most of the world.

Story aside, the general idea here is that magic is somewhat unstable. Not hugely unstable, just a little bit. Magic still works for the most part, but every once in a while a caster's spell might fizzle, be more powerful than expected, or shower the target in very small lizards.

I'm not sure how to implement that. I don't want to make casters unplayable or much weaker at all, I care mostly about fluff. I also don't want to be arbitrary about it, I'd much prefer it be entirely random, maybe with some way for players to influence the outcome.

The system I'm thinking of using is as follows.

When a caster casts a spell, roll [some kind of die. (d100/d20?)] On a [result (1-2 on d20, 1-10 on d100?)], roll on [table (Sorc wild magic table? Rod of Wonder table?)] for random magical effect. If a spell is cast as a ritual, or by adding one extra minute to its casting time, a caster can be sure that no random effect will occur.

A few obvious questions here:
1. What kind of chance should there be for instability?
2. Should I use a pre-existing table, or make my own?
3. What kind of effects would be appropriate? Nothing too significant, mostly fluff, but a little bit of crunch as well.

Hopefully I've phrased this comprehensibly. :)

[Louro]

Unstability ratio: (spell slot level) x 2%
So, cantrips are safe, and the more power you draw from the magic fabric the higher the chance of things going wrong.

Mechanic: one spell one roll.
To keep it easy and fast, if a spell requires an attack roll it doesn't trigger the random effect.
(Possible unbalance here)

Get a d100 table for effects, so players don't know what the effects can be and they don't easily repeat.

[Occasional Sage]

Why not simply take the Wild Magic sorcerer tables from the PH and apply them to all casters? It seems like you're wanting to reinvent the wheel, and that amount of effort needs justification. You mention the tables yourself, what is falling short?

[Naanomi]

I'd use the wild magic table as well, maybe 1-2% per spell level?

[Keltest]

I would just use the wild mage table as well. Possibly tweak it for different classes a little bit depending on how much they rely on pumping out spells compared to, say, stabbing someone.

[Kane0]

Mirroring what is said above.
Cantrips are risk free, spells are 1% chance per spell level. If they roll an attack roll you roll the % and vice versa for spells with saves, that way theres less time taken rolling dice.
Use the wild magic sorcerer table, and expand or change it as time goes on so people don't clue on to what numbers match what results.

[Rusvul]

Thanks for the help. I think Spell Slot Level x 2% instability is a good ratio. It adds more substantial risk to higher level spells, while keeping lowbie characters mostly safe.


Why not simply take the Wild Magic sorcerer tables from the PH and apply them to all casters? It seems like you're wanting to reinvent the wheel, and that amount of effort needs justification. You mention the tables yourself, what is falling short?

Two reasons- One, because the Wild Magic table relies on the DM to choose when it activates- I'd rather it not be in my control when a spell goes wild, I feel like that could seem kind of arbitrary, especially since one of my players is new to D&D. Two, because I don't want to rob Sorcerers of their uniqueness. To that end, because I intend to give other classes a chance for wild magic, would it seem reasonable to allow actual Wild Magic sorcerers to reroll their 1d100 if they so choose, then forcing them to take the second result?

ie, level 1 Wild Magic Sorcerer rolls on the table and finds that they're going to be fireballed due to wild magic. So they use their reroll, roll again, and instead summon butterflies.

Thoughts? Maybe that would be better as a x/day thing?

[Louro]

I would delete the wild magic sorcerer because every caster is a wild magic sorcerer.

Giving them an edge to control the unstability goes against their very "thing". Instead the ones who cannot control their magic, they will be the ones with more control over the randomness.

[Naanomi]

Though it would be interesting for a wild Mage alive during the cataclysm... Goes from being unable to control his magic to one of the only living casters with an 'understanding' of the new magical chaos

[Louro]

He he, good point.

[Kane0]

Though it would be interesting for a wild Mage alive during the cataclysm... Goes from being unable to control his magic to one of the only living casters with an 'understanding' of the new magical chaos

Very much so, but said mage would have to be several thousand years old to have been a wild mage prior to the wildifying of magic during the surge.

[ImSAMazing]

Very much so, but said mage would have to be several thousand years old to have been a wild mage prior to the wildifying of magic during the surge.

He was a Warforged!

[Naanomi]

He was a Warforged!
Or a lich... A dreadful villain once ridiculed for her magical bumbling but now the only 'living' true master of the chaos left. What if only she knows the secrets to truely stop it? What would convince her to share that knowledge if it took away the benefit of her 'gift'?

[Rusvul]

The Eladrin, (Who, in this setting, are somewhere between 4e Eladrin and Aasimar, as this setting has a sort of Fiend/Fey duality rather than Fiend/Celestial. Haven't statted them out yet.) who once controlled the plane, are biologically immortal. Those who know that they ever existed are almost entirely sure that they were all either wiped out or fled back to their home plane... But there could very well be a powerful renegade who existed before the Fall. That's an interesting idea... He could be a BBEG... Heh. That'd be fun.

[Steampunkette]

I dunno... I feel like Wild Mages would work just fine.

The kit gives the Sorceror increasing control over luck, chance, happenstance, and wild magic surges. Maybe take away some of their low level "Random Happens out of your control!" power (like the Wild Magic Roll itself) and give them some more control over wild magic. Specifically: Give them the ability to force wild magic surges.

It changes their style only slightly, and makes them wilder than other casters by default.