Ok, I've now skimmed through all the spells in the PHB and read all the responses here (thanks everyone!). I found 40 spells that use Dex Saves (For those interested I've attached the list. I've probably missed some, but there's only a certain level of thoroughness I'm willing to invest
). Of those only 6 (Blade Barrier, Conjure Barrage, Conjure Volley, Cordon of Arrows, Hail of Thorns, Ice Storm) seemed like obvious fits for AC Saves to me (though I can still see differences of opinion on that). Another 3 (Acid Splash, Guardian of Faith, and Wall of Thorns) I could easily make an argument for either way. Some of these spells actually have similar spells, like Melf's Acid Arrow, that use a Spell Attack Roll.
Whatever the case, I think an AC Save would have is uses for Area of Effect (such as Conjure Volley, and just regular volleys) but the confusion caused by interaction with other effects (buffs to saves, conditions, etc.) makes me think that, as a few people have suggested, I should just use plain attack rolls for these spells. I'd consider instead having a Defence Roll (essentially the exact same thing but mechanically it counts as an Attack Roll so bonuses would be applied to the other side) but for the confusion I think it would cause it might just be quicker to roll an Attack Roll for each player in turn after all.
Sadly it just doesn't feel right to me for the players to roll an Attack Roll on the GM's/another player's behalf and hope for a low roll. I guess I can't win every time!
I was still thinking some DEX saves (ie fireball not web), a shield proficient character not proficient in DEC saves could get proficiency & use the higher of the shield's +2 or his own DEX mod. I didn't mean to imply that choosing to use a good DEX mod sacrificed proficiency.
Aaah I see, I like this as an ad-hoc bonus actually. I think if a player asks and sets the scene of them sheltered behind their metal shield I'd happily grant the +2 vs a spell like Fireball.
I'd look at changing the spells themselves rather than introducing an AC save. Using volley of arrows as an example, if it normally requires a Dexterity saving throw then instead change it to a ranged spell attack.
I think I may well do this, I just wish there was a better way of handling area of effect attacks than using the same hit roll for all targets, rolling each target individually, or getting the players to roll it on my behalf... maybe I just need more dice... why didn't I think of this 2 days ago?
Yes traps made the attack. In 4e the attacking creature or trap always rolled whether it was a melee, ranged attack or spell. The rolled attack targeted either the AC, reflex, willpower or fortitude defences depending upon the type of attack. Saving throws only existed if you had been hit by an attack which had an ongoing effect which a save could end (and saves in 4e was a simple unmodified d20 roll, with 11 or above being a success).
I just like the idea that the attacker rolls the dice - that the randomness is in their hands rather than the defender. I am not sure that it matters where the randomness is in real terms, but I do prefer a unified system where all attacks are resolved in the same way rather than a mix of attack rolls and saves in 5e (for eg).
Ah I see. Thanks for sharing your 4e insight, it's interesting to see how they changed things around, especially as it does sound somewhat simpler. I like the sound of it but also the idea of the players having as many rolls as possible relative to the GM. I don't think I want to be making an Attack Roll per character in an Area of Effect either :/
I'm all for an AC save, as your argument for it makes sense.
Although it is the same as rolling an attack roll against each target excepting for edge cases such as Sharpshooter and the likes.
Unfortunately I'm rolling back on it now! xD The edge cases are actually a pretty big reason, I could call it a Defence Roll and say anything that applies to Attack Rolls applies but in reverse... I think my players would yell at me
I'm generally in favor of DMs using whatever mechanics they want to model things in whatever way is appropriate. 5E can sometimes be myopically focused on just the three canonical types of rolls (attack/ability/save) and it's nice to see DMs thinking out of the box. If you were my DM and you said, "Conjure Volley is now an AC save", I'd be fine with it once I understood what an AC save was and how it works.
(If I were running it though I would probably make Dex save proficiency not apply to AC saves, because Dex is already factored into AC, and the things I imagine using an AC save for, like a hail of arrows, require a different defense mode than things I would require a Dex save for, like falling off a cliff or dodging a specific arrow. If Dex save proficiency should apply, then it shouldn't be an AC save at all. Basically, I just don't want the complication of cross-proficiency for saves and don't see what it buys you.)
Not every random roll has to be tied to an ability score in order to make sense.
I agree on dropping the Dex Proficiency bonus. Unfortunately I've also decided that with so many interactions with other effects and spells, the AC Save doesn't make much sense after all for me. >.< I feel like I've caused a big debate for no reason, hopefully it was a fun one at least and yeah, outside the box!
There are other spells that increase your AC as well such as Shield of Faith and Haste. And, if Indie had been wearing plate mail I could have seen the darts just bouncing off. Or have him hold up some kind of big improvised shield and the darts hitting the shield instead of the adventurer.
Don't get me wrong, from an in-play perspective AC feels different. If it didn't involve so much rolling, I'd make AC a defense rolled by the player. It would certainly feel more dynamic, I just think it would slow down the game too much.
Because of the complications of interactions with spells like Shield of Faith and Haste I've actually now abandoned the idea. Having AC a defence rolled by the player is pretty much where I was going with it though, I think it would speed up Area of Effect attacks tremendously. Maybe there's still something to be tested in that...
Likewise, there are things that will apply disadvantage to attack, but not advantage to a conceptually comparable save, or vice-versa. And there are things which will do both. It's...
...inconsistent.
One of consequence of returning to the complexity of arbitrarily assigning attacker-rolls mechanics to resolving some attacks and defender-rolls mechanics to others.
Would it? Instead of the DM making one roll per attack, the player does? Same number of rolls, and it's not like players have a lot of demands on their time between their turns...
I've decided there are enough inconsistencies in this game to make my head spin for a week. A lot of them do seem to add to the fun though!
But then it's the player doing the rolling.
This is all I wanted! Why is it never so simple?
