What does the Catapult spell's Dex saving throw do?

Question

The object flies in a straight line up to 90 feet in a direction you choose before falling to the ground, stopping early if it impacts against a solid surface. If the object would strike a creature, that creature must make a Dexterity saving throw. On a failed save, the object strikes the target and stops moving. In either case, both the object and the creature or solid surface take 3d8 bludgeoning damage.

From what is written above, it seems to imply that succeeding the saving throw means the object still deals it's 3d8 damage, but can continue to fly forward, potentially damaging additional targets. It actually seems ideal from the caster's perspective for the enemies to succeed their saving throws if they are in a line.

Is that really what happens? RAI it seems obvious that the spell should not damage targets that succeed the saving throw, but our group is trying to go with as much RAW as possible. You could even mitigate the damage dealt to the projectile by using something especially sturdy, like adamantine.

Answer 1

As you've noticed, the key sentence to deconstruct is the last one.

In either case, both the object and the creature or solid surface take 3d8 bludgeoning damage.

"In either case" refers to the case where the projectile is stopped by "stopping early if it impacts against a solid surface" versus the case where it is stopped by "the object strikes the target and stops moving".

Then the rest of the sentence is straightforward: "both [the object] and [the creature or solid surface] take 3d8 bludgeoning damage" - [the creature or solid surface] will refer to whichever stopped the projectile, and both that and the projectile itself will take 3d8 damage.

Answer 2

"In either case" refers to the following two cases:

• "it impacts against a solid surface"
• "the object strikes the target" (not "the object would strike a creature")

Answer 3

FYI - this has been updated in Xanathar's and the language has changed slightly. Now, it says "On a failed save, the object strikes the target and stops moving. When the object strikes something, the object and what it strikes each take 3d8 bludgeoning damage."

If the caster is able to line up multiple targets within the range, then if the first one saves that first target takes no damage at all - they have dodged the bullet. The next in line will also have to make a Dex save to dodge. And so on until someone fails or the max range is reached. Only the projectile and a max of one target / object will take damage, and only if they are within range and they fail their save.

Answer 4

On a successful save, the character or creature isn't hit, it keeps going to finish the 90ft. If the creature is the target, then they just avoided getting hit, but what ends up getting hit still takes 3d8 damage.

Yes you are right, if there are several creatures in a line before the 90 ft is up, someone is very likely to eventually get hit.

Answer 5

This is very badly worded.

I will attempt to use English grammer and sentence parsing rules, and no attempt to divine the intent of the rules based on the game mechanics.

An incomplete set of possible pairs of "cases" that could be referred to are:

1. (the object is stopped by a solid surface) or (the object is stopped by a creature)

2. (the object flies to 90 ft and falls to the ground) or (the object is stopped by something)

3. (the object impacts a solid surface) or (the object would strike a creature)

4. (the creature makes the saving throw) or (the creature fails the saving throw)

5. (the object flies 90 ft) or ((the object impacts a solid surface) or (the object would strike a creature))

In English, to determine which pair of cases we are referring to, we would use symmetry and context.

Symmetry wise, 1 and 4 win out. 1 is symmetrical because both involve a "stop". 4 is symmetrical, because it involves failing/passing the same thing. 2 and 3 fail to have any symmetry that 1 and 4 lack.

5 is very asymmetrical, with one branch of the either case carrying 2 sub branches. Barring an extreme set of contextual clues, it is not "either case".

Context wise, 4 is ruled out: there is no solid surface involved in that case, and the "either case" is supposed to have a solid surface involved.

So reading it in an intention-agnostic way, the English used imply that case 1 is the most likely interpretation.

Either case defaults to symmetry, because you are referring to two things in an interchangeable way. Referring to extremely different things interchangably requires more contextual clues in English to be "good form".

Answer 6

I'm not sure if there is a Sage Advice answer to this, but I think if you break down what is listed in the context of the entire spell, it makes sense. This spell is like a life lesson on Newton's laws of motion.

• Choose one object weighing 1-5 lbs within range that isn't worn or carried. This 1-5 lb object then flies in a straight line up to 90 ft before it falls on ground.

• 1st case for spell ending before the object has flown 90ft:

  If there is an unavoidable solid surface in the object line of motion (like a 30ft foot wall or a building) when it hits that surface the object stops moving.

• 2nd Case for spell ending before the object has flown 90ft:

  If instead of a wall/tower/building/etc there is a creature in the path of the object, that creature can make a dexterity saving throw to avoid getting hit. If they fail the Dex save the object hits them and stops moving.

In either case where the object hits something, we get to see Newton's 3rd law in action. The object and whatever it hits while still in motion, be it a creature or a wall, take 3d8 damage due to the impact force of the moving object's momentum.