For me, it absolutely depends on the setting.

TSR D&D's system makes sense with wizards having so few spells. AKA, a mage must develop significant skills to manage their magic, thus slow progression.

DCC hits a happy medium as the average roll will give you basic results and things only go wonky on high/low rolls.

I do like wild magic effects, but that's also setting dependent.

In general, "push your luck" systems work if the mages can cast at-will. If the spells are locked in silos (D&D) or based on energy points (RQ, T&T and Palladium), then its less fun to spend your resource to have nothing useful happen.

Quote from: AsenRG;1033737Personally, I assumed you're reserving the tables fora supplement;).

No, like I said, I don't think 'random mishap tables' is really proper for Medieval-authentic magic.

Quote from: RPGPundit;1033931No, like I said, I don't think 'random mishap tables' is really proper for Medieval-authentic magic.

Well, that's too bad. But then it means I can come up with my own:D!

Quote from: AsenRG;1033967Well, that's too bad. But then it means I can come up with my own:D!

Yup, you're certainly welcome to. I just wrote my game, but it's YOUR campaign!

Quote from: RPGPundit;1033931No, like I said, I don't think 'random mishap tables' is really proper for Medieval-authentic magic.

I dunno. What if your wizard whacks a big guy in the head while swinging his smelly shoe around trying to turn invisible?

Quote from: RPGPundit;1034387Yup, you're certainly welcome to. I just wrote my game, but it's YOUR campaign!

That's right. I bought it with the intention of using it for setting info in my campaign, so it's working as intended:)!

Quote from: Krimson;1034425I dunno. What if your wizard whacks a big guy in the head while swinging his smelly shoe around trying to turn invisible?

That's a matter for the Reaction Table thread;).

Quote from: AsenRG;1034528That's a matter for the Reaction Table thread;).

What if the Reaction Table WAS the Spell Mishap Table? [/Keanu]

Quote from: Krimson;1034533What if the Reaction Table WAS the Spell Mishap Table? [/Keanu]

Then you'd know you're playing Dungeon World:D?

Quote from: AsenRG;1034543Then you'd know you're playing Dungeon World:D?

I haven't actually been able to read through that yet.

Quote from: Krimson;1034425I dunno. What if your wizard whacks a big guy in the head while swinging his smelly shoe around trying to turn invisible?

In Lion & Dragon that certainly could happen, but it wouldn't be the result of a mishap roll, it would be something that happened while the magister was engaged in the shoe-twirling stage of casting his invisibility spell, thus disrupting the spell and forcing the magister to start the casting process all over again.

Quote from: RPGPundit;1032885Do you want totally predictable magic, in the style of Vancian-casting D&D, where what you readied you cast, and it will be guaranteed to go off?

Or would you rather it be unpredictable, in the style of DCC, where a roll determines whether the spell even works or how well?

Do you want your magic to be zero-cost; or would you rather that it drained hit points or ability scores to cast? Or maybe something else, some deeper cost to make magic effective?

Depends.

When working on Black Book I did it so that most spells drain random HP: you use Burning Hands or Charm, you suffer 1d4 drain. Wizards get a Mana buffer, but if you don't have enough you lose Vitality Points (replenishes quickly and mostly represents exhaustion and minor injuries), and then Wound Points (harder-to-recover-mostly-meat-points).

You can also opt to boost spells by suffering more drain, but you roll before the spell goes off, so it's possible to knock yourself out (or even die) before the spell goes off.

I suggested changing the system to something more Vancian at one point, but the players really dug random drain so I just left it as-is. On that note, I'm working on another D&D hack where it'll be more Vancian, but it'll differ in that wizards will have x total spell slots, and spells will take up y slots, and you can let them take up more slots to make them do bigger things.

I guess I don't really prefer one over the other (though I prefer both over traditional D&D), it's more how magic is explained in game. I can see the pros of both: former you could roll lucky and cast more spells, plus you could get really lucky and throw down a really big spell without falling over first, but the latter would be faster/easier to deal with I think.

I think spell failure rolls can have a similar effect on magic users that critical hit/failures can have on fighters: i.e. on a long enough timeline, somebody is going to get hurt and that ultimately effects players more than NPCs.

Mages exploding is not necessarily a bad thing, I hasten to add. If that is the milieu that you are going for, then great. However, it is worth knowing in advance and bearing in mind that your "cataclysmic spell failure" doesn't produce effects that wind up being undesirabe.

Recently I read a friend's copy of Wonder & Wickedness, an OSR supplement for magic that contains some great stuff but also a list of "Spell Catastrophies" that contain a few examples of what I try to avoid. I am referring to the type of spell failure that may do the following things:

1) Affect a wide area detrimentally affecting many innocent bystanders

This can be problematic. To begin with it makes the practice of magic fundamentally immoral, which is not necessarily unworkable in itself but players wishing to play a White Wizard or Good Witch might feel disappointed that there is no place for that archetype in your setting. Again, worth talking over with your players, Otherwise you might get this:

Good Witch Player) I plave my hand on the wounded diseased peasent and mutte in the Old Language the incantation of purification. *rolls dice*
GM) Oh. A fumble. So instead of a shining light, the sun eclipses and before your eyes the plague spreads rapidly from villlager to villager and the plants wither and the soil turns to ash. Then you see the deceased villagers rise as walking dead. Mwahaha. Isn't this fun.
Good Witch Player) I think I might retire this character


Even without the blight and zombies, this sort of occurence begins to produce plot holes, so to speak. If a fumble just inflicts disease in a one mile radius and the range is a 1 in 20 or even a 1 in 100, then the cure disease spell is not only useless, it is a time bomb. Iake the standard 1 on a d20: Curing a dozen people has a high probability of infecting ten or a hundred times that amount. This spell makes the spell worse than pointless. It is actually counter-productive,

The plot holes I mentioned begin to appear when the players think to themselves: "Hang on, if magic can cause such calamity it must have done so before we came on the scene. In that case, why does anybody use it and why would anybody let a magic user live?

Which is fine if you want a campaign in which all magic is evil and the players know that, if they want to play a wizard,  they have to play a psycopath on the run.

Be aware however that the catastrophe can also means it could be weaponised. All you need is brainwashed acolytes from a death cult  or humanoid shamans with a deathwish and you have your fantsay suicide bomber. Even a low level magic user could keep casting spells in the hope of setting off one of the various effects frequently listed in spell fumble charts: i.e. summons demon, opens gate, curses the land et. al. Low level magic users capable of high level effects.

Which brings me to my next point.

The effect of the spell calamity being WAY more powerful than the actual spell that was miscast.

The idea that an apprentice is only capable of intentionally creating a soft glowing light and putting a handful of people to sleep, but is unintentionally capable of triggering an earthquake is not in itself invaild: Indeed the classic Mickey Mouse apprentice in Fantasia nearly floods a castle by accident. However, what is good for fiction and what is good for gaming are not necessarily the same thing. Besides the weaponisation of spell fumbles that I mentioned earlier,   there are other ways that this has the potential to undermine your game. Granted that its a nonsense to talk about logic when discussing imaginary use of magic. That being said, some sort of internal consistency does facilitate the suspension of disbelief: therefore dangerous magic would mean that it was practiced far away from civilisation because a simple math of wizard x spells/day means that spell fumbles would be a weekly if not occurence. EVen if your spell fumble table only has a 1% chance of brining catastrophe, it would happen within a few years at the latest.

Moreover, considering that apprentices have to practice to learn their magic, then it begins to look less and less plausible that they would ever make it to the level of jouneyman.

Permanent effects on PCs.

I am talking about the "you grow horns, a third eye, tentacle" sort of thing. This is totally up to the people running their game and the milieu they want to set their game in. In fact this is hardwired into DCC which is great, However, the players and GM should all be on the same page on this one. "No Galadriels or Garions but lots of Ningaubles" should be explicitly agreed upon.

In the Wonders and Wickedness catasrophe tables there are also similar effects on the people around the spell caster, which could be a bit irksome if your fellow player has just given you an extra limb with suckers on it.

More than level loss, ability score drain or even loss of limb, can this piss on a player's chips if it comes unexpectedly. The players should be aware that there is a risk that comes with having a wizard in the party.


So this is why I am thinking of the following guidelines when I create a magic mishap system:

• The effect of the failure should not be more than one spell level more (or less) than the spell that was miscast.
• The effective casting level of the spell should not be any more than two levels of the caster.
• The effect of the fumble is either related to or an inversion of the intended spell. (i.e. no casting healing and summoning a fire elemental).

Examples:

A first level magic user who miscast the first level Light spell could produce: a Darkness  15 foot radiues cast as if a third level magic user. Alternatively a Continual Light but on the caster's (or an ally's) eyes, or even a Pyrotechnics effect centered on where the Light spell would have been cast.

A third level magic user who miscast the third level Fireball spell could produce: a Wall of Fire, an Ice Storm a Create Water (cleric spell)

A tenth level cleric who miscasts Raise Dead could produce a Finger of Death on himself or an NPC, Disintergrate on the targeted corpse, Gease or Quest on the cleric or another PC

A sixteenth level Magic User miscasting Monster Summoning VII gets Gate and at this point you can go full Armageddon if you like.

DISCLAIMER: not telling anybody that they are having badwrongfun. Just my two cents.

I do quite like the characteristic from DCC where you roll to see if a spell succeeds, and if it does you can continue casting it. It was a big reason why I included spell/prayer checks in Lion & Dragon.

Ive been enjoying reading the Magisters' magical skills.:cool: IIRC Ars Magica tried something similar in the 4th edition of Hedge Magic but it was not as satisfying IMHO.

Quote from: Mike the Mage;1036052Ive been enjoying reading the Magisters' magical skills.:cool: IIRC Ars Magica tried something similar in the 4th edition of Hedge Magic but it was not as satisfying IMHO.

I'm very glad you like it. As I've mentioned before, it's all based on real rituals from medieval grimoires.

The ritual for invisibility was especially amusing to me.