D&D 5E What is a Dex save doing?

[The Crimson Binome]

I feel like this is only a problem when using Grid Play. Grid-less play, being more concerned with relative positioning than exact positions, can easily accommodate small changes in fictional positioning that make sense for the circumstances at hand.

Grid-less play doesn't mean your positions aren't fixed. It just means your fixed positions aren't worth drawing on a map.

If you're playing gridless, a save against fireball doesn't mean you were actually halfway out of the area. The underlying reality within the game world doesn't change depending on how you go about describing it, and whether or not you use a grid to do so. It's the same territory, regardless of which map you're using.

 

[The Crimson Binome]

And why does whatever you're doing not cost your reaction, not cost movement, and not change your fictional positioning (e.g. make you go prone)?

The short answer is that it's tradition. The long answer is that they failed to update the tradition to go along with the rest of the changes to the system.

Back when Gary was running the show, making your save against a dragon's breath weapon meant that you had moved around the corner or hidden behind a rock. Combat rounds were a minute long, so there was no point in tracking position down to the foot, since everyone was constantly moving around. Dodging an explosion didn't require your movement or reaction or anything, because it was all just subsumed into the chaos of melee.

When they introduced the grid, and especially when they went to the six-second round, that stopped being a reasonable assumption. Instead of saying that you are in a general area over the course of a given minute, now we're saying that you're effectively within this specific five-foot square over the course of six seconds. Our problem is over-constrained. There's not enough wiggle room left for anyone to hide behind a rock or around a corner, given that we know their position with such precision. And besides, now that we have reactions (which are used for things like opportunity attacks), it really seems like it would take your reaction to interact with the incoming flame.

So we're left grasping at straws. We need to figure out some explanation for what's going on within the game world, such that the rules we've inherited will still do an adequate job of describing that, even though the original explanation doesn't make sense anymore.

 

[Fanaelialae]

The short answer is that it's tradition. The long answer is that they failed to update the tradition to go along with the rest of the changes to the system.

Back when Gary was running the show, making your save against a dragon's breath weapon meant that you had moved around the corner or hidden behind a rock. Combat rounds were a minute long, so there was no point in tracking position down to the foot, since everyone was constantly moving around. Dodging an explosion didn't require your movement or reaction or anything, because it was all just subsumed into the chaos of melee.

When they introduced the grid, and especially when they went to the six-second round, that stopped being a reasonable assumption. Instead of saying that you are in a general area over the course of a given minute, now we're saying that you're effectively within this specific five-foot square over the course of six seconds. Our problem is over-constrained. There's not enough wiggle room left for anyone to hide behind a rock or around a corner, given that we know their position with such precision. And besides, now that we have reactions (which are used for things like opportunity attacks), it really seems like it would take your reaction to interact with the incoming flame.

So we're left grasping at straws. We need to figure out some explanation for what's going on within the game world, such that the rules we've inherited will still do an adequate job of describing that, even though the original explanation doesn't make sense anymore.

Eh, it's not that great an explanation anyway IMO.

Assume that a fighter is in melee with a giant and they're both caught in a fireball. Both make their saving throws and survive. Is it really so believable that they both ran away, hid behind a rock/corner, and then both ran back and rejoined melee? What if there isn't cover sufficient for a giant's stature in the vicinity?

Personally, that strains my credulity more than saying that they both managed to raise their shields or duck inside their cloaks, thereby avoiding the brunt of the fireball's heat.

 

[Tony Vargas]

Someone casts Fireball. You make your Dex save and take half damage. Why?

'Reacting in time,' I'd say. Exactly what that looks like, I'd probably visualize much as EGG described it in the 1e DMG. So a caster might interfere with a quick counter-spell, while a fighter crouches behind his shield or powers through it by "sheer defiance," etc.

Should it be a 'reactions?' Maybe conceptually, but the Reaction is far too limited in the action economy for that to be at all workable.

 

[FormerlyHemlock]

'Reacting in time,' I'd say. Exactly what that looks like, I'd probably visualize much as EGG described it in the 1e DMG. So a caster might interfere with a quick counter-spell, while a fighter crouches behind his shield or powers through it by "sheer defiance," etc.

Should it be a 'reactions?' Maybe conceptually, but the Reaction is far too limited in the action economy for that to be at all workable.

I like this interpretation. It hints at a way of describing the difference between Dex save AOEs (Red Dragon breath) and Con save AOEs (White Dragon breath). I need to think more about this, but thanks, Tony.

 

[Dausuul]

'Reacting in time,' I'd say. Exactly what that looks like, I'd probably visualize much as EGG described it in the 1e DMG. So a caster might interfere with a quick counter-spell, while a fighter crouches behind his shield or powers through it by "sheer defiance," etc.

Should it be a 'reaction?' Maybe conceptually, but the Reaction is far too limited in the action economy for that to be at all workable.

That's how I interpret it too, and I don't see any need to make it a reaction. You don't need a reaction to block an axe with your shield, or to use your Dex bonus to dodge a dragon's claws; no more do you need one to duck when a fireball comes sailing toward you.

Reactions are limited to more "committed" responses.