The Sorcerer can discriminate between invisible targets provided that they know the invisible targets are there

Once you are aware of an invisible creature, provided they are not hidden, you know where it is (because they are still making noise, kicking up dust, etc.) but you cannot, in general, see them.

If a spell specifies that you have to be able to see the target, then you have to be able to see the target.

Conversely, if it does not require you to be able to see them, then you can target them, so long as there is a clear line of sight/line of effect to the target [i.e. there isn’t a wall in the way].

The situations where you can see an invisible target are limited. Some examples of when you can see an invisible creature are:

• you have alantern of revealing
• you havetruesight
• you have blindsight
• some environmental effect, like heavy rain, is silhouetting the invisible creature

For the specific case of theSlow spell, since it does not have the “that you can see” qualifier, the Sorcerer can discriminate between targets that they know are within the area of effect.

So in your example, if they know the invisible BBEG is there and the BBEG is not hidden, then they can choose to only target the BBEG.

• \$\begingroup\$Comments are not for extended discussion; this conversation has beenmoved to chat.\$\endgroup\$

  doppelgreener

  – doppelgreener

  2018-07-12 13:22:26 +00:00

  CommentedJul 12, 2018 at 13:22

RAW: So long as they know the target is within the cube, then it can be done.

Beyond just the RAW: (Not so much RAI in-and-of itself, but you can see it in the same vein.)

However, let's say they were following a character who took levels inRogue and hasCunning Action. Presuming you were treating things as though the characters were in Combat, regardless of if it was expressly stated or not, you could say it went like this:

1. Target walks down street.
2. PC is following on their "turn".
3. Target castsInvisibility on himself.
4. Target usesCunning Action to take aDash action to get away.
5. PC catches up to the area he last saw the Target in and castsSlow in a given area.
6. Target is outside the Area of Effect and is therefore unaffected bySlow.
7. PC wouldn't know if the spell worked or not and would have to decide how to proceed with this uncertainty. Depending on if the Target notices or not, a formal Combat order could begin.

This is just an example for showing the other side of the coin. In this case, the spell fails. In your scenario, the spell succeeds. If it was a matter ofSlow specifying "that you can see", the Slow spell would then fail, but it doesn't. Essentially, all theInvisibility did was add another layer of potential failure to theSlow spell. Instead of the target simply having to succeed a Wisdom ST, now the caster has to be sure they are including their target in the area of effect or else it fails, and the PC won't know whether it failed because they missed or if their target succeeded the roll, which makes continuing their actions all the more difficult.

• 3
  \$\begingroup\$Invisible creatures still make noise and leave tracks if they are not hidden (they haven’t taken the hide action). In combat, it is assumed that you know where your enemies are unless they try to hide from you. Being invisible gives the creature to hide in plain sight, but it doesn’t make them silent. Swapping out the Dash action for the Hide action would make the answer more relevant to the question. Alternatively having a character that can misty step as a bonus action would be able to achieve the end result you are using in your example.\$\endgroup\$

  illustro

  – illustro

  2018-07-12 12:57:55 +00:00

  CommentedJul 12, 2018 at 12:57
• \$\begingroup\$@illustro, that requires taking the time (and cost of 1 Action) to roll Wisdom (Perception) to look for tracks or listen for sounds, assuming the Target isn't making an obvious ruckus. Seeing as they are in the middle of a city, neither would be easy to do in regards to an invisible target. Even if we assumed the city was only as busy as a small town's farmer's market, that still is a quite a bit of noise and quite a few people moving around. The environment would reasonably be in favor of the Target's escape unless there was actual reason for the PC to know exactly where the Target is.\$\endgroup\$

  Sora Tamashii

  – Sora Tamashii

  2018-07-12 13:23:42 +00:00

  CommentedJul 12, 2018 at 13:23
• \$\begingroup\$Either way, it doesn't matter our stances on the subject. We're both effectively arguing RAI at this point as the rules don't specify how exactly to treat an Invisible character who hasn't hidden yet. Even still, as you said, swapping Dash with Hide in my example would work towards that end anyways. So, it's really a pedantic argument for you or I to be making, hence why I didn't respond to you saying the same things to ily in your comments... because it really doesn't make a difference in this case.\$\endgroup\$

  Sora Tamashii

  – Sora Tamashii

  2018-07-12 13:26:28 +00:00

  CommentedJul 12, 2018 at 13:26

The spell description only states it affects an area (as you point out) and you can choose up to 6 targets within it. It doesn't specifically state that you have to be able to see the targets.

By contrast, other spells such aspolymorph specifically state "a creature that you can see within range".

More generally, the rules say only that you must have a clear path to the target, so it can't be behind total cover. But again, visibility is not mentioned; only a spell requiring an attack roll would be affected due to rules about attacking a creature you can't see.

You've already received plenty of sufficient answers for your genericCan I cast Slow on an Invisible Target question, but you also ask a hypothetical about a school bus which hasn't received an answer.

You could not do this with your school bus hypothetical

The other answers focus on the need (or lack thereof) of line-of-sight. Some spells do, some spells don't, but the default answer is "does not require." This is not the case withline-of-effect, where "does require" is the default. In the scenario that prompted this question, the line-of-effect is clear: you could draw a straight line between you and your target without intersecting anything else, invisible or not. There are no obstacles, and there are no people in the way.

What would stop yourSlow from hitting its target isfull cover, which blocks line-of-effect. D&D has never provided a great rule about when you're in full cover and when you're not, butJeremy Crawford has, somewhat controversially, said that glass (such as a school bus window) provides full cover. You could not castSlow into a school bus:

A solid obstacle, regardless of material, can provide total cover. A closed window counts.

If you were talking about a school bus with, say, shattered windows, it's down to a DM call: what level of cover does this mass of innocent school children provide? There is no clear answer.

• 1
  \$\begingroup\$What happens if the school bus is invisible? Does it still block line of effect? What if it's invisible and you don't know it's there? Can I hide behind an invisible school bus and be immune to spells?\$\endgroup\$

  Racheet

  – Racheet

  2018-07-13 12:12:51 +00:00

  CommentedJul 13, 2018 at 12:12
• 1
  \$\begingroup\$@Racheet Silly as it seems, wouldn't the answer be yes, according to RAW? Crucially, D&D5 in most situations makes no distinction between cover due to physical restrictions and cover due to sight restrictions. They are both just cover.\$\endgroup\$

  Michael W.

  – Michael W.

  2018-07-13 17:04:00 +00:00

  CommentedJul 13, 2018 at 17:04
• \$\begingroup\$The answer is simple, a glass window is visible yet you can see through it, and it DOES NOT work, the same logic can be applied with an invisible glass, you can see through it but the spell will be blocked by the window. so Same logic with any other material. Since you didn't know though, you can still do it but it will detonate/end on the invisible wall/structure/bus that's all and you'll lose a spell slot, if it's not invisible you can still do it but the target is the object, and that would be a waste of a spell slot.\$\endgroup\$

  Maxpire

  – Maxpire

  2019-12-31 09:11:23 +00:00

  CommentedDec 31, 2019 at 9:11

• dnd-5e-2014
• spells
• invisibility
• targeting