How important a mechanic is arcane spell failure (ASF)?

[Endarire]

How important a mechanic is arcane spell failure (ASF)? I know it's been adapted from earlier editions where arcanists couldn't cast in armor at all, or only in specific armors. In 4e and 5e, the mechanic was removed. I also know this was done to enforce the 'Wizards wear robes/clothing into battle instead of leather/metal armor' trope.

In 3.5, ASF is mostly a hindrance to the low-level Sor/Wiz who can't yet have mage armor active pretty much all day, a Githcraft Feycraft Mithril Chain Shirt, or similar means of negating ASF. Other arcane casters like Bards, Warmages, and Dread Necromancers ignore ASF of light armor. Divine spells, psionics, and other magic systems normally have no such spell failure chance.

One rarely-discussed balancing factor of armor and shields is that they're heavy. A chain shirt is 25lb. Sor/Wiz normally have low STR scores. Putting more points into STR usually means less to allocate elsewhere.

(As an aside: I normally ignore ASF when I'm GMing.)

What say you?

[rel]

I've always thought of it as a rule that enforces theming; It keeps the wizard in cloth.

As you say, there are many ways to easily add armour AC to an arcane caster so it doesn't really affect balance one way or the other.

If you want a world where wizards can wear plate, ditch ASF. If you want robes and pointy hats, leave it in.
Both are good options, it really depends on the game.

[Vaern]

Honestly, the fact that spell failure chance only applies to arcane magic doesn't make a lot of sense to me. It's flavored as interfering with somatic components and causing spellcasting to fail, but if that's the case then it should apply to divine spells with somatic components as well.
As a house rule I'd probably ignore ASF altogether if they're proficient with whatever armor they're wearing. If your sorcerer goes out of his way to take armor proficiency feats it's kind of annoying for him to also have to go out of his way to sift through class features, feats, special materials, equipment templates, and armor properties to find a way to effectively use a piece of equipment that he is proficient in using.
Conversely, I'd also apply the penalty of spell failure chance to divine casters and such who are not proficient with their armor. This won't really have too much impact on divine casters as clerics and paladins are proficient with all armor, and druids can't use metal equipment which means they need to jump through some hoops to even make armor that they are not proficient in available to them. They still aren't at significant risk of falling victim to spell failure, but at least this way it's not just by nature of being divine casters - it's simply because their class is trained to function proficiently in those types of armor.

[Psyren]

I personally think it's important to have a mechanic that explains why most wizards/sorcerers (and monks for that matter) in the default setting go around wearing robes when just about anything else would be more practical. With that said, I'm not sure ASF is the best way to do that; it's an arcane system (no pun intended) that either forces a bunch of clunky extra rolls if interacted with, or book-diving to bypass it.

5e's system is more elegant but a bit draconian - if you're wearing armor you're not proficient with, you can't cast spells at all, period, and that goes for divine casters too. My ideal would probably be a broad and easy-to-remember on/off switch like that, but not as hard a limitation as "no spells" - perhaps instead, nonproficiency would mean every spell requires an additional move action on top of whatever action it takes to cast normally.

[FaerieGodfather]

I think they're supposed to be an important balance mechanic, but the ease of bypassing it (via non-armor defenses) trivializes it.

I would say that three feats is about right for Heavy Armor, but not when you can get those three feats via a single class level. Or spend a single feat and a single class level to add your spellcasting ability to your AC. (Unless you're a Sorcerer.)

[Mr Adventurer]

Armour is basically garbage outside of carefully built edge cases. In one game I'm in, we had Defense Bonus from Unearthed Arcana, and nobody wore armour except a couple of heavy-armour users. The saving on encumbrance, Speed, check penalty, and WBL were too good to pass up. In the end, the DM house ruled Medium and Heavy armour: Medium armour doesn't penalise Speed, and both Medium and Heavy armours offer 1 more point of AC than normal. It helps.

[Zaq]

It’s almost a weird emergent thing. The starting point and the ending point are not the same.

In my experience, I’ve never seen anyone roll an ASF check. (Yes, I’m sure someone, somewhere has rolled one, but never near me.) No one I’ve ever seen tries to cast spells without removing ASF, whether by not wearing (normal) armor or by mitigating the ASF down to 0.

Basically, the weird/interesting part is that it’s not absolute. There are ways around it. Classes that let you ignore it, materials that reduce it, clever ways to avoid somatic components, etc. So some arcanists use mage armor or whatever like the devs intended, while others find a way to wear armor without being affected by ASF. But again, in my experience, no one actually rolls ASF.

It’s not so much that it prevents wearing armor outright—more that it adds a weird set of costs to folks who want to cast spells without being (numerically) naked. Two sets of armor with different ASF chances are viewed not so much as “armor A is riskier to cast in than armor B” but more like “it costs more build resources to cast in armor A than in armor B, and I won’t wear either until I have the necessary resources lined up.”

As far as removing it goes? It’s fine. Ruins nothing, really. There’s still a ton of penalties for wearing nonproficient armor (including, but not limited to, ACP applying to initiative, which matters a lot), so characters who would be subject to ASF still need to expend resources getting proficiency if they really want to clank around in metal clothes. Basically turns wizards and sorcerers into psions for the purposes of dealing with armor. Sure, you can hide your psion in full plate with a big-ass shield... if you like always going last and never firing rays.

[ezekielraiden]

Like almost all limitations in 3.PF, it's a noble idea undercut by its clunkiness and crushed beneath the weight of a thousand splats that nickle-and-dime it out of existence one way or another.

I have, personally, achieved AC of greater than 60 as a non-epic spellcaster (admittedly gestalt though). I have achieved AC greater than 80 as an epic caster character without trying that hard (and without actually using any epic spellcasting, as we never got enough money/XP to pay for learning a single spell and the DM hard-banned spells with non-epic spellcraft DCs.) So ignoring ACF is generally as easy as "cast a few spells to take care of it." The more durable, but also more tedious, way to ignore it is with build choices (class features, feats, and items), but it can still be done on most any character. It's why a level of spellsword (ignore 10% of ACF, advances casting) is squeezed into nearly any gish ever--you lose almost nothing and the prereqs are trivial for a gish.

So...yeah. It's a typical 3.5e limitation: thin as tissue-paper for anyone prepared to address it, but clunky and restrictive for anyone who actually grapples with it.

[Asmotherion]

Other than theme enforcing it's also a slight balancing factor considering how an Armor/Shield can be enchanted and thus an unavailable "slot" for the mage.

There are options to reduce ASF for "that mage who wants to use armor". if you ignore it it changes those options to irelevant.

And let's be honest: How stronger does a Full Caster really needs to be?

[Malphegor]

How did it work in AD&D, anyway? Most of the 3e rules like that in the phb are based on prior editions. I'm curious how the previous editions handled 'wizards wore robes and pointy hats' to prevent 'wizards wear power armour and CRUSH PUNY MORTALS'

[Mr Adventurer]

Hmm. If your armour is non-magical, does it still take your Body slot? Would be cool if no, layering a robe over plate metal or vice-versa could be a cool look. Limited actual use, though.

[Asmotherion]

How did it work in AD&D, anyway? Most of the 3e rules like that in the phb are based on prior editions. I'm curious how the previous editions handled 'wizards wore robes and pointy hats' to prevent 'wizards wear power armour and CRUSH PUNY MORTALS'

To be fair even a Mid-Low OP Wizard in his underwere still Crushes Puny Mortals. The Robes is more of a Fashion Sence.

Also some of your colegues may snob you if you don't wear robes the same way that in real life you're expected to at least master the basics of style or be seen as the creepy guy who's mom still dresses him up.

[rel]

Other than theme enforcing it's also a slight balancing factor considering how an Armor/Shield can be enchanted and thus an unavailable "slot" for the mage.

There are options to reduce ASF for "that mage who wants to use armor". if you ignore it it changes those options to irelevant.

And let's be honest: How stronger does a Full Caster really needs to be?

It doesn't really adjust the balance much. applying special materials and crafting techniques onto light armour and shields can give your wizard slot access fairly trivially.
And the cleric and druid are both full casters with unrestricted spell list access and the ability to wear armor so it isn't really a balance against casters just wizards.

[Crake]

Honestly, the fact that spell failure chance only applies to arcane magic doesn't make a lot of sense to me. It's flavored as interfering with somatic components and causing spellcasting to fail, but if that's the case then it should apply to divine spells with somatic components as well.

The way I've always understood it is that arcane casters are actually casting the magic themselves, and thus need to be precise in their motions, wheras divine casters are channeling the power of their deities, and thus just need to get the correct general motions to channel that power, rather than getting it perfectly correct.

[DrMotives]

How did it work in AD&D, anyway? Most of the 3e rules like that in the phb are based on prior editions. I'm curious how the previous editions handled 'wizards wore robes and pointy hats' to prevent 'wizards wear power armour and CRUSH PUNY MORTALS'

Been a long time since I played an earlier edition, but as I recall, any arcane spell with an S in the component line was simply uncastable in armor, full-stop.

[rax]

Been a long time since I played an earlier edition, but as I recall, any arcane spell with an S in the component line was simply uncastable in armor, full-stop.In AD&D 2e only elven mages wearing elven chain (which couldn't be bought, only found or given as a reward) could cast spells in armour. Clerics could cast in any armour and other divine casters could cast in whatever armour their class allowed them to wear.

[Alent]

This seems like a good thread to ask about an idea I've been considering for a while now.

Since ASF causes unnecessary slowdown over the table, any ideal replacement should theoretically be passive, something that doesn't impact game flow in combat but still makes you hesitate to choose heavier armor. Why not just replace ASF by applying ACP to CL and Spellcraft checks?

[Mr Adventurer]

This seems like a good thread to ask about an idea I've been considering for a while now.

Since ASF causes unnecessary slowdown over the table, any ideal replacement should theoretically be passive, something that doesn't impact game flow in combat but still makes you hesitate to choose heavier armor. Why not just replace ASF by applying ACP to CL and Spellcraft checks?

It should apply to Concentration too.

Otherwise it might be OK.

[ExLibrisMortis]

This seems like a good thread to ask about an idea I've been considering for a while now.

Since ASF causes unnecessary slowdown over the table, any ideal replacement should theoretically be passive, something that doesn't impact game flow in combat but still makes you hesitate to choose heavier armor. Why not just replace ASF by applying ACP to CL and Spellcraft checks?
I think Jowgen explained how ASF doesn't appear at the table. So it's already passive enough.



If I wanted to redo the armour system, I'd get rid of ASF/ACP, and probably the distinction between armour weights, replacing them with other things. If I wasn't redoing the entire system, ASF wouldn't matter enough to be worth changing. You could get rid of it, or you could not get rid of it. *shrug*

[Daefos]

This seems like a good thread to ask about an idea I've been considering for a while now.

Since ASF causes unnecessary slowdown over the table, any ideal replacement should theoretically be passive, something that doesn't impact game flow in combat but still makes you hesitate to choose heavier armor. Why not just replace ASF by applying ACP to CL and Spellcraft checks?

I definitely like the idea of a more passive penalty, this seems to create more lore problems than it really solves. Why would a wizard who dons a set of full plate suddenly find themselves unable to remember how Fireball works?

Perhaps just putting a hard limit on the level of spells you can access while wearing armor? Light armor prevents you from casting your highest level of spells, medium armor from casing your highest two levels of spells, and heavy armor your three highest. You can still manage to wiggle out a magic missile on full plate if you’re practiced enough, but the more advanced Black Tentacles is too tricky. The numbers may need tweaking, but I think that’s perhaps a decent starting point.

[thelastorphan]

I definitely like the idea of a more passive penalty, this seems to create more lore problems than it really solves. Why would a wizard who dons a set of full plate suddenly find themselves unable to remember how Fireball works?

Perhaps just putting a hard limit on the level of spells you can access while wearing armor? Light armor prevents you from casting your highest level of spells, medium armor from casing your highest two levels of spells, and heavy armor your three highest. You can still manage to wiggle out a magic missile on full plate if you’re practiced enough, but the more advanced Black Tentacles is too tricky. The numbers may need tweaking, but I think that’s perhaps a decent starting point.


I think that these two ideas feel the same. They both reduce your ability to cast in a flat way. A caster level penalty doesn't have to remove your ability to cast spells, but it could make them easier to dispel and do less damage. Since those are other things based on CL.

All in all I think a hard limit on where you can go feels a bit wrong. It's really the material and magical reductions that cause trouble. If you could only access ASF reduction through feats and class features that would be a good start as well. If you actually care about wizards wearing armor.

[Vaern]

The way I've always understood it is that arcane casters are actually casting the magic themselves, and thus need to be precise in their motions, wheras divine casters are channeling the power of their deities, and thus just need to get the correct general motions to channel that power, rather than getting it perfectly correct.
Probably. I'm not seeing anything regarding divine casters and somatic components in the PHB that states why divine spells are explicitly exempt from spell failure chance, but it does mention that bards are able to wear light armor with arcane spell failure chance because the somatic components of bard spells are simpler than other arcane spells. There's also a footnote on arcane casters and armor which calls wizards and sorcerer spells as requiring particularly complicated gestures. A divine caster's somatic components must be as simple as brandishing a holy symbol or making a vague gesture towards the target of their spell.

[FaerieGodfather]

This seems like a good thread to ask about an idea I've been considering for a while now.

Since ASF causes unnecessary slowdown over the table, any ideal replacement should theoretically be passive, something that doesn't impact game flow in combat but still makes you hesitate to choose heavier armor. Why not just replace ASF by applying ACP to CL and Spellcraft checks?

High Adventure Role-Playing uses a power point system similar to the 3.X psionics system... and armor imposes a power point penalty to spellcasting, raising the PP cost of each spell you cast and imposing the corresponding penalty(-5% per PP) as augmenting your spell. It doesn't have the same PP cap as psionics, though, being based on your ranks in the spell rather than caster level.

[GrayDeath]

Well, due to the reasons mentioned (or at elast most of them) we replaced ACF with something simple:

First you need the actual proficiency to wear armor/Sheidls, and D&D Characters are notoriously feat starved as is (PF much less so), especially if you want some metamagic.

Secondly, casting in armor makes you tired. So we put in a limit of the number of spells Arcane Casters can cas tin armor before they need to stop, sit down, and relax for some time (it predated the short rest mechnaic of later editions by quite a bit, but is not totally the same anyway, so yeah ^^).
Meaning every 7 Spells in light, every 6 in medium and every 4 in heavy armor.
If they didnt, the exhaustion meant they lose 2 pts of CL until they do.

Simple, even slightly balancing, not easily avoidable due to what the armor is made of, and still if you want a fully armored Wizard, you can have one: ;)

[AnimeTheCat]

How did it work in AD&D, anyway? Most of the 3e rules like that in the phb are based on prior editions. I'm curious how the previous editions handled 'wizards wore robes and pointy hats' to prevent 'wizards wear power armour and CRUSH PUNY MORTALS'


Been a long time since I played an earlier edition, but as I recall, any arcane spell with an S in the component line was simply uncastable in armor, full-stop.

According to my stained 2e book (and baldur's gate enhanced edition) DrMotives seems correct. You just can't. I dont even think it needs the S component, you just cant. Just like you couldn't use thief skills in any armor heavier than studded leather.

[Mato]

Q: How important a mechanic is arcane spell failure (ASF)?
A: It delays, and increases the personal cost, of an arcane spellcaster from obtaining a reliable defense against the most wide spread method of killing someone.
1. Does the ability to circumvent this later on invalidate it's usage earlier in the game? No.
2. Do casters need more stuff? No.
3. Are there builds about an arcane spellcaster expressly progresses in for AC benefits? Yes.
It's hard to say how important, but it is important.