We were playing Out of the Abyss, and a player got engulfed by a Gelatinous Cube. The spellcaster asked to take him out with telekinesis.
In previous editions, I would have ruled they had no line of effect, but it seems in 5e you need only line of sight.
After a few arguments, I allowed it, but I'd like to know how I should have done it.
As per this answer,
In a podcast, [Jeremy Crawford] confirmed that you can't target creatures with spells beyond transparent obstacles because spells require a connection between caster and target.
Because the target has total cover, then they cannot be targeted. Crawford also tweets this regarding conjuring animals across an invisible Wall of Force. Conjuring spells require no attack roll, and no saving throw. They specify "a spot that you can see", but Jeremy confirmed that this means you need both uninterrupted line of effect, and to see where you are casting! The Gelatinous Cube does offer total cover, thus negating Telekinesis.
Creatures inside the cube can be seen but have total cover (MM p.242)
This also falls within the general Spellcasting rules.
To target something, you must have a clear path to it, so it can’t be behind total cover.
Spellcasting rules don't actually require sight, because you can target invisible enemies or enemies that you cannot see, according to rules of combat.
When you attack a target that you can’t see, you have disadvantage on the attack roll.
So spells need to specifiy when sight is required.
Regarding the specific beats general rule, it's about direct contradictions. Remember that the spells say "a target that you can see", and not "a target that you only need to see". They are essentially re-enforcing the targeting conditions already existing on spellcasting rules, meaning that targets need to be visible and that there must be an uninterrupted line between them and the caster. Otherwise you could cast spells at invisible targets within range, and roll Attack Rolls with only disadvantage if you could guess their location properly. An exception would be Sacred Flame, that explicitly contradicts the cover rule:
Flame-like radiance descends on a creature that you can see within range. The target gains no benefit from cover for this saving throw.
Keep in mind that certain spells have specific ranges in order to be able to target things that are not visible, or under cover. Dream has Special range, Telepathy has Unlimited range, Locate Object and Misty Step have Self range. Telekinesis, on the other hand, has 60ft range, and Conjure Fey has a range of 90ft.
That being said, the Rule of Cool would be a great application here. Possibly adding a casting check against the Cube's Strength DC (as if someone was physically trying to pull the player out). But this falls under homebrewed rules and DM judgement.
Strictly speaking, no, as the engulfed creature has total cover and therefore cannot be targeted to be picked up.
However, given that the gelatinous cube description specifically allows its victim to be pulled away from it with a simple strength check without reference to the grappling rules, it would not be unreasonable to rule that removing the victim from the cube with telekinesis could be done with the "steal an object" mode of telekinesis. A potential bonus on a strength check (casters tend to be weak) and avoiding some acid damage doesn't seem out of line for a use of a 5th level spell.
I would think it shouldn't be an automatic success though. Have them make a check with their casting stat vs the cube's rescue DC.
Can you telekinesis a friend out of a gelatinous cube?
Telekinesis (PHB p.280) (emphasis mine)
When you cast the spell, and as your action each round for the duration, you can exert your will on one creature or object that you can see within range, causing the appropriate effect below.
Gelatinous Cube (MM p.240 and p.242) (emphasis mine)
A gelatinous cube is all but transparent (p.240)
Creatures inside the cube can be seen but have total cover (MM p.242)
Yes, if you have the appropriate vision to see in the lighting conditions and you are in range you can use Telekinesis on a creature trapped within a cube.
Telekinesis has no Saving Throw. It has no Attack Roll. If you can see it, you can manipulate it. Period. The only limitation is that creatures caught in your telekinesis can struggle against it, using a Strength Check to determine the outcome.
This is quite different than the sorts of things that Jeremy was addressing in his podcast. Whether Jeremy's pronouncement still applies is well within the realm of "DM's discretion". I don't believe that Jeremy means to prevent an Unseen Servant from operating on the other side of a glass window or Mage Hand from letting me grab a goldfish out of a glass bowl. And Telekinesis seems more like those spells than any others in the book. But reasonable people can disagree, both on Jeremy's overall intent and on its applicability to the specific spells.
Call me "old school," but it seems pointless to debate the rules or to look for precedence by supposed experts. My experience comes from AD&D 2nd Edition, but the idea remains the same: when all is said and done, remember that it is a game, and it's meant to be fun.
The "rules" are mere guidelines to help the DM craft the most enjoyable experience for the players. So, do not take them as law.
And if you're unsure how to interpret the rules, then it's time to take charge and make the decision yourself based on what fits your world the best.
