AC's of Spells


Rules Questions


Im not sure if this is covered anywhere but I was curious on the idea of spells having active ACs. Take Fireball for instance, you point your finger at your desired target, and "A glowing, pea-sized bead" fires off at your target. If the bead hits something before arriving at a target, it goes off early.

Lets say we have a person who sets a readied action for said Wizard. Readied action is to fire an arrow at any projectile "fired" by said Wizard. Wizard points, Fire bead streaks towards target. Can it be intercepted by an arrow, seeing the arrow can be "something the bead hits to set it off early" what AC would you have to hit for this to happen?

Silver Crusade

AC 18. The "pea-sized bead" would be a Fine object, height/length 6" or less, +0 Dex bonus because it's not actually trying to get out of the way, nor is it immobile, and no other modifiers as far as I can see.


But the archer should probably just ready to shoot the wizard and interrupt the spell instead.


Rylden wrote:

Im not sure if this is covered anywhere but I was curious on the idea of spells having active ACs. Take Fireball for instance, you point your finger at your desired target, and "A glowing, pea-sized bead" fires off at your target. If the bead hits something before arriving at a target, it goes off early.

Lets say we have a person who sets a readied action for said Wizard. Readied action is to fire an arrow at any projectile "fired" by said Wizard. Wizard points, Fire bead streaks towards target. Can it be intercepted by an arrow, seeing the arrow can be "something the bead hits to set it off early" what AC would you have to hit for this to happen?

Not possible, just as it isn't possible for someone to shoot an opponents ammunition of the air.


@OldSkool Toxophilite Rangers have a skill that allows hitting enemy ammo, "Intercept Arrow (Ex)", so the ruling that hitting enemy ammo cant be done is crazy, second it you cant hit enemy ammo you cant deflect arrows, as per deflect arrows requiring you to hit(automatically of course) said projectile out of the air.


Rylden wrote:
@OldSkool Toxophilite Rangers have a skill that allows hitting enemy ammo, "Intercept Arrow (Ex)", so the ruling that hitting enemy ammo cant be done is crazy, second it you cant hit enemy ammo you cant deflect arrows, as per deflect arrows requiring you to hit(automatically of course) said projectile out of the air.

Let me clarify, it isn't possible without a special ability to allow it. The examples you gave for instance. If anyone could just target the bead of a fireball then just anyone could target an arrow in flight to deflect it. Those require feats to accomplish and those feats are specific about the attacks coming from a ranged weapon. So until there is a feat that allows you to target a spells projectile then you can't.


Fair points, what about Sunder, anyone can sunder at anytime, I can sunder an arrow laying on the ground, because its moving does that mean i cant?


Basically. Take deflect arrows or similar feats if you want to do that.


Rylden wrote:
Fair points, what about Sunder, anyone can sunder at anytime, I can sunder an arrow laying on the ground, because its moving does that mean i cant?

That would be correct. There are feats that allow you to interact with projectiles in flight.


CampinCarl9127 wrote:
Basically. Take deflect arrows or similar feats if you want to do that.

They still won't let him hit the bead of a fireball to set it off early, presumably in the caster's face.


OldSkoolRPG wrote:
CampinCarl9127 wrote:
Basically. Take deflect arrows or similar feats if you want to do that.
They still won't let him hit the bead of a fireball to set it off early, presumably in the caster's face.

My comment referred to attacking arrows, not spells.

Liberty's Edge

If you're looking for an option to deflect spells out of the air, there's Smash from the Air, which still doesn't work on fireball, because it only affects spells with attack rolls. Good for rays though.


Fireball has an attack roll if your behind something that narrows line of sight, like Arrow Slits.


Deighthon Thrane doesn't represent the feat fully correctly.

I'd throw the player out of my game who argued that you could use the feat to deflect a fireball, since it was cast from behind an arrow slit and not from infront of it...


I know the feat well, and looked it up to be sure, but the whole behind this arrow slit was a joke, sorry. Not sure how to show humor in text. Id throw out a gamer who said that as well. haha


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Rylden wrote:
Not sure how to show humor in text.

Bah, today's kids are so spoiled by emojis they have lost its predecessor, the ancient art of the emoticon! Tilt your head to the left when looking at these. Noses are generally optional.

:-) happiness

;-) wink and a smile, this is probably what you wanted

:-( sadness

:-\ sympathetic "eh" (note: nose mandatory)

There are innumerable variations. Just never, ever, type a mirror-image emoticon (where the viewer would have to tilt their head to the right). It's just wrong. ;)


Fuzzy-Wuzzy wrote:
Rylden wrote:
Not sure how to show humor in text.

Bah, today's kids are so spoiled by emojis they have lost its predecessor, the ancient art of the emoticon! Tilt your head to the left when looking at these. Noses are generally optional.

:-) happiness

;-) wink and a smile, this is probably what you wanted

:-( sadness

:-\ sympathetic "eh" (note: nose mandatory)

There are innumerable variations. Just never, ever, type a mirror-image emoticon (where the viewer would have to tilt their head to the right). It's just wrong. ;)

LoL, LMAO, or even a JK would work too!

Whippersnappers just don't know how good they got it!.

Silver Crusade

Personally, I would have allowed it because while there ARE feats that allow you to do something fairly similar, the main point is that you readied your action to do it, which is a fairly inefficient use of your turn. The feats let you deflect arrows and such as a free action, you don't use any of your own efforts on it.


Personally I'd rule DM "circumstance penalties or bonuses" for it being so small, moving fast, and you not having the feats to even do so with an arrow let alone a spell.

I'd say you get roughly an AC of 15+CL+Dex, so somewhere upwards of 20-35 depending on the level of the wizard and how high their dex is. It's not an easy shot, but it's very creative and most certainly representative of a number of movie scenes (a recent not-hero shooting a grenade comes to mind), so I'd love to allow it if you have the moxy to pull it off. Big payout too, if you can catch the enemy wizard and a few mooks unaware I might even make their reflex at a penalty (perhaps no dex to their reflex save for being basically flat footed/flanked).


As a GM, I would say go for it. The AC to hit would not be only AC18, that Fireball spell is able to travel 400ft. plus in a round. That is very fast and a hard target to hit. I would add +1 to the AC for very 30ft. the fireball could travel farther than an average person 30ft. Say it is a 10 level wizard shooting that fireball; so 30-(400+(40x10))=770/30=25.666 round to 26 plus the base 18 gives an AC 44 for the fireball. By the way that fireball is traveling as fast if not faster than your arrow, so the best I would give you is the fireball goes off at the half way point. To hit that on a twenty you would need a +22 to hit with that bow. Your archer is giving up a full round attack to ready an action to maybe stop that fireball if the wizard even uses fireball. As a GM, I say go for it.

Silver Crusade

I don't agree with giving it a bonus to AC for having a higher speed. Do you give monks, air elementals, or creatures under the effects of Expeditious Retreat a bonus to AC because they can move fast? Dexterity specifically measures how good you are at dodging out of the way, which the fireball CAN'T do.


@Tursic

Assuming your level 10 Wizard fires his fireball, ONE fireball in a single round, and it travels max distance, of as you mentioned 800'. Your stating this is faster then a arrow, however, given a Ranger with Archery feats, and Overwatch Style feats, he can fire 4 arrows in that same round at 110' per range increment, more if your adding flight arrows. So in the first 8, out of his possible 10 increments hes fired 4 arrows in the time it takes for a fireball to make that distance, and had them travel further.

You can look at that same Ranger taking Toxophilite archetype which has rules for interception range attacks. Mechanic wise its set to deal with Physical weapons, however it wouldnt be a stretch to use it as a guide line for attacks such as a fireball.

As Val'Bryn2 stated your Dex mod is what could be your "speed bonus to AC" not your actual speed. Otherwise Expeditious Retreat, Cheetah Sprint, etc would all grant a bonus to AC, in addition to the movement.


Val'bryn2 wrote:
I don't agree with giving it a bonus to AC for having a higher speed. Do you give monks, air elementals, or creatures under the effects of Expeditious Retreat a bonus to AC because they can move fast? Dexterity specifically measures how good you are at dodging out of the way, which the fireball CAN'T do.

Although Monks deserve the extra AC, especially if they are a low-level or pack a STR build.


Val'bryn2 wrote:
I don't agree with giving it a bonus to AC for having a higher speed. Do you give monks, air elementals, or creatures under the effects of Expeditious Retreat a bonus to AC because they can move fast? Dexterity specifically measures how good you are at dodging out of the way, which the fireball CAN'T do.

Your monk doesn't routinely break 66.6'/second. I don't say impossible, but I do say hitting a marble traveling more than 6 times as fast as I can move is an epic accomplishment, and the rules for sized fine objects start at things much bigger than the fireball in flight. The game doesn't really have good rules for high speed, and doesn't really account for targets that small. So there's some DM leeway here to make things difficult, in fact there's plenty of room for a DM to simply say "no, that's never gonna happen. Just shoot the caster and hope he fails his concentration." but it's a neat idea, and attributing a difficulty and a slim chance of success to it makes it an awesome moment in that character's story. The birth of a legend, because if I toasted a wizard, scorched his book, and took out two of his henchmen by putting an arrow through his fireball, or even took out two minions on their advance midway between me and the wizard, I'd have my bard announce me as "Insert-name the Firebreaker" from then on when talking to important people.


Rylden wrote:

@OldSkool Toxophilite Rangers have a skill that allows hitting enemy ammo, "Intercept Arrow (Ex)", so the ruling that hitting enemy ammo cant be done is crazy, second it you cant hit enemy ammo you cant deflect arrows, as per deflect arrows requiring you to hit(automatically of course) said projectile out of the air.

Actually Rylden you have only quoted half of the Toxophilite archetype ability. The second to last sentence lists a number of things that you can NOT deflect/intercept.

Intercept Arrow (Ex): At 3rd level, a toxophilite can ready a ranged attack to deflect a ranged weapon attack against her or an ally within 30 feet. ... The toxophilite must declare the use of this ability after the attack is announced, but before the roll is made. Unusually massive ranged weapons, such as boulders or ballista bolts, and ranged attacks by firearms or generated by natural attacks or spell effects can’t be deflected. This ability replaces endurance.


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Do not try to bring physics into Pathfinder. It always ends in madness. Always.

Spoiler:
Not to mention your physics is bad ;)


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CampinCarl9127 wrote:

Do not try to bring physics into Pathfinder. It always ends in madness. Always.

** spoiler omitted **

Ends in madness? No, it starts with Touch of Madness. In the middle, there is Confusion. It ends with the Barbarian mauling your corpse for 8d6+96 damage.


@Cerhiannon Your 100% correct in the quote of the skill, which is why later in my post I say that the rules are for intercepting range attacks, Mechanic wise its for Physical attacks, and could be used as a guide line for magical ones, not that this ability would work for this idea.


It has been discussed before.
Readied Action to Tackle a Fireball

The fireball should have an AC of around 18. Possibly I'd add in the caster's Dex if they were already trying to shoot past the intercepting character (ie. he was already in the path, as opposed to his readied action moving him into the path.)

Grand Lodge

in my games, I allow any character to try this (intercept fireball pea, or an arrow)...

IF they use a hero point (karma points, favor card, ... any specific & rare consumable)

otherwise, there are indeed power / feats that allow you to do it on a regular basis.


Vrischika111 wrote:

in my games, I allow any character to try this (intercept fireball pea, or an arrow)...

IF they use a hero point (karma points, favor card, ... any specific & rare consumable)

otherwise, there are indeed power / feats that allow you to do it on a regular basis.

Now that I could go with. Readying an action isn't a significant investment to do something that normally requires a feat. Spending a Hero Point is, so that I would consider allowing.

Grand Lodge

I for one would allow a player to ready a action to Shoot down something like this. I would also allow them to shoot down enemy weapons if they can destroy it with one attack. For the fireball I would make it ac 18+ caster Mod so if it was a wiz with a 18 Int it would have a ac of 22 and only 1 hp. I see this as a weaker counter spell in a way. I would have it hit at the 1/2 point of where it was fired from and where it should have gone off.

Rember that hitting it will make it go off where it was hit and could be a interesting effect on its own.


DeathMvp wrote:

I for one would allow a player to ready a action to Shoot down something like this. I would also allow them to shoot down enemy weapons if they can destroy it with one attack. For the fireball I would make it ac 18+ caster Mod so if it was a wiz with a 18 Int it would have a ac of 22 and only 1 hp. I see this as a weaker counter spell in a way. I would have it hit at the 1/2 point of where it was fired from and where it should have gone off.

Rember that hitting it will make it go off where it was hit and could be a interesting effect on its own.

If you do that then there is no reason to ever take the deflect arrows feat, the ranger archetype or any other ability that protects from ranged weapons. If anyone can do it why waste the feat, feature or spell on it?

This also really impacts the alchemist class. After the first bomb any group of enemies is going to have at least one member ready an action to target his bombs.

Also there are no rules for where it would hit in the trajectory. You say at the 1/2 point. Players are definitely going to use that to pull shenanigans allowing them to get effects to go off where they normally wouldn't such as alchemist fire in mid-air between flying enemies.

Also the AC of the projectile is irrelevant. A wizard or a UMD character with a wand of Magic Missile can hit it every time.

Allowing this is one of the worst ideas I have ever heard in 20+ years of gaming.

Grand Lodge

I am not sure about the Ranger archtype or another that give the ability as I woould have to see it but the feat lets you do this for free where without the feat you are burning your action to do this. If you see them doing this change tatics as you see them doing it. If you are the wiz and you see the archer use his standard action to shoot it down you instead hit them with a Magic missile instead.

I do not see this blocking range attacks I see it as destorying the attack and fireball is one of the spell that would be hit with this. Lighting bolt for instance would not or Magic Missle would not be effected at all but would wast thier actions.

As to a wand of Magic Missile it would not work as "Objects are not damaged by the spell." To me the Bead would be a Object in this case.


DeathMvp wrote:

I am not sure about the Ranger archtype or another that give the ability as I woould have to see it but the feat lets you do this for free where without the feat you are burning your action to do this. If you see them doing this change tatics as you see them doing it. If you are the wiz and you see the archer use his standard action to shoot it down you instead hit them with a Magic missile instead.

I do not see this blocking range attacks I see it as destorying the attack and fireball is one of the spell that would be hit with this. Lighting bolt for instance would not or Magic Missle would not be effected at all but would wast thier actions.

As to a wand of Magic Missile it would not work as "Objects are not damaged by the spell." To me the Bead would be a Object in this case.

It is worth burning the action to be able to accomplish this and getting to take another feat in that slot. So now I can still deflect arrows and take a different feat.

It is your game so if you want this house rule go for it. It is an absolutely terrible house rule but one you are free to make.

Silver Crusade

OldSkoolRPG wrote:
DeathMvp wrote:

I for one would allow a player to ready a action to Shoot down something like this. I would also allow them to shoot down enemy weapons if they can destroy it with one attack. For the fireball I would make it ac 18+ caster Mod so if it was a wiz with a 18 Int it would have a ac of 22 and only 1 hp. I see this as a weaker counter spell in a way. I would have it hit at the 1/2 point of where it was fired from and where it should have gone off.

Rember that hitting it will make it go off where it was hit and could be a interesting effect on its own.

If you do that then there is no reason to ever take the deflect arrows feat, the ranger archetype or any other ability that protects from ranged weapons. If anyone can do it why waste the feat, feature or spell on it?

This also really impacts the alchemist class. After the first bomb any group of enemies is going to have at least one member ready an action to target his bombs.

Also there are no rules for where it would hit in the trajectory. You say at the 1/2 point. Players are definitely going to use that to pull shenanigans allowing them to get effects to go off where they normally wouldn't such as alchemist fire in mid-air between flying enemies.

Also the AC of the projectile is irrelevant. A wizard or a UMD character with a wand of Magic Missile can hit it every time.

Allowing this is one of the worst ideas I have ever heard in 20+ years of gaming.

The point of the feats is that you can do it for free, with this you're impacting party action economy to ready for the spell, IF they cast that spell. Readying an action to shoot the fireball doesn't do anything if they cast lightning bolt, for instance.

And as for this being the worst idea you've ever head, I've got 4 words for you: sword of true strike. We've all heard that one, and it's far worse.


Val'bryn2 wrote:
OldSkoolRPG wrote:
DeathMvp wrote:

I for one would allow a player to ready a action to Shoot down something like this. I would also allow them to shoot down enemy weapons if they can destroy it with one attack. For the fireball I would make it ac 18+ caster Mod so if it was a wiz with a 18 Int it would have a ac of 22 and only 1 hp. I see this as a weaker counter spell in a way. I would have it hit at the 1/2 point of where it was fired from and where it should have gone off.

Rember that hitting it will make it go off where it was hit and could be a interesting effect on its own.

If you do that then there is no reason to ever take the deflect arrows feat, the ranger archetype or any other ability that protects from ranged weapons. If anyone can do it why waste the feat, feature or spell on it?

This also really impacts the alchemist class. After the first bomb any group of enemies is going to have at least one member ready an action to target his bombs.

Also there are no rules for where it would hit in the trajectory. You say at the 1/2 point. Players are definitely going to use that to pull shenanigans allowing them to get effects to go off where they normally wouldn't such as alchemist fire in mid-air between flying enemies.

Also the AC of the projectile is irrelevant. A wizard or a UMD character with a wand of Magic Missile can hit it every time.

Allowing this is one of the worst ideas I have ever heard in 20+ years of gaming.

The point of the feats is that you can do it for free, with this you're impacting party action economy to ready for the spell, IF they cast that spell. Readying an action to shoot the fireball doesn't do anything if they cast lightning bolt, for instance.

And as for this being the worst idea you've ever head, I've got 4 words for you: sword of true strike. We've all heard that one, and it's far worse.

You guys keep focusing on fireball which is only one spell. Because you see that as being less of an issue. That is a misdirect though because the whole argument hinges on allowing the shooting of projectiles without a feat. You can use it on enemy arrows and alchemist bombs. An alchemist doesn't have a choice between fireballs and lightning bolts. You just have to ready an action to shoot whatever he throws.

Also this is allowing you intercept missiles that aren't even targeting you. Something even the feats can't do. So one party member can use their action to shut down an enemy ranged attacker or alchemist regardless of who that enemy is targeting.

But it is a house rule anyway and this is a rules discussion forum so I'm done with the discussion anyway. As long as it ends up fun at your table go for it. I would not enjoy that game but that's me.

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