Can Thorn Whip be used to hang an enemy in combat?

Question

I am not sure how would I handle this, it was quite a surprise.

A party member was able to sneak above an enemy under a tree, successfully Thorn Whipped him under said tree from 20ft height, with advantage, even passed the additional roll of grabbing the enemy by the neck, and then jumped off the Thorn Whip hanging over the branch, effectively yanking the enemy's neck I assume.

I solved that by adding (weight / 25) damage to the attack of Thorn Whip, and then went by rules of choking (enemy goes unconscious after 1 + con mod turns) for as long as the player was able to hold on and keep up the weight on the "rope".

Did I take the right approach or are there rules I missed?

Answer 1

Thorn Whip normally cannot be used this way, due to its duration.

From what you described, the player character cast thorn whip to grab an enemy by the neck, and used gravity and a branch to hoist up their opponent, all while holding on to the whip.

However, as written, thorn whip has an instantaneous duration, which means there is no "holding on" to the spell. Once the whip has pulled the creature, the spell ends. The spell does not last long enough to strangle a creature or to be used as a climbing rope.

Going by the written rules, what should have happened was as follows:

1. Character casts thorn whip, successfully attacks the enemy, causes piercing damage.
2. The enemy is pulled 10 feet upwards. The game mechanics do not differentiate how they are pulled, whether by the neck or arm or leg, they are treated the same way.
3. Thorn whip ends. Enemy falls 10 feet downward, which may result in falling damage.

As the other answers point out, you have discretion as DM over how things work in your games, so you can certainly allow creative use of spells and other features. Flexibility is generally an asset for DMs. Although be mindful with these rulings, as too much flexibility with the rules could eventually lead to issues with game balance or other disagreements between players.

Answer 2

Did I take the right approach ...

Absolutely. You are the DM and you described the results of the character's actions. Well done.

... or are there rules I missed?

Absolutely. There are no secret rules; so there is no secret rule in Thorn Whip allowing it to go around someone's neck and choke them or, for that matter, to create any effect that lasts longer than the turn on which it is cast. What Thorn Whip does is:

If the attack hits, the creature takes 1d6 piercing damage, and if the creature is Large or smaller, you pull the creature up to 10 feet closer to you.

That's it, that's all, there ain't no more.

I would have ruled that you could drag the target 10 feet up and they would then fall down; taking 1d6 falling damage. But it's your table, not mine.

Answer 3

You're the DM so the answer is usually going to be YES

BUT...

You added a lot to the abilities of the Thorn Whip spell:

• It now lasts longer than one turn
• It now grapples an opponent
• The opponent couldn't (apparently) try to break the grapple but was now doomed with no way to save themselves.

All that aside though, the DM rules the table as long as they can justify their rulings.

And the rule of cool still trumps everything else.

The only issue is the need to be consistent about these things across all sessions. So although creatively coming up with solutions is fine (and to be encouraged) it can create more issues if you're too lenient.

Answer 4

No, this was a poor approach

All the "you're the DM, so you decide" answers are technically true, but they miss the bigger picture, that you've just created a homebrew rule that is entirely unbalanced.

Thorn Whip is a cantrip that deals 1d6 damage, and increases by 1d6 at the usual cantrip levels. This means that it will deal between 1 to 6 damage.

Now you add weight / 25 damage to the mix. Let's assume we're dealing with a relatively average person of 175 lbs. That's a flat +7 damage, which is absolutely ludicrous. A cantrip that deals 1d6+7 damage is not balanced in the slightest. Warlocks can get 1d10+5 with some investment, and everybody knows how that ends up, with warlocks essentially just spamming Eldritch Blast the entire game and not much else. And that's a "relatively average person", once players catch on to this gimmick, expect them to start carrying their max carrying capacity before doing this trick for an easy extra + 4 damage. Or making heavier characters. You could easily get a flat +20 damage if you make a Goliath druid who carries his max capacity.

Then, on top of that, you ruled that they can instantly KO somebody if they can manage to hold on for 1+monster's CON turns AND they're essentially grappled in the air, so taken out of the fight? All for the low-low cost of a single cantrip.

Going for the 'rule of cool' is great, but you have to realize that you're setting a precedent here. You've taken a cantrip meant for dealing some minor damage and crowd control, and made it one of the deadliest assassination tools in existence.

A Champion NPC has 143 HP, +2 CON and a CR of 9. With your new Thorn Whip rules, a single low level druid can take him out in 3 turns. This will drastically unbalance the game if the Druid starts using this more often, which makes it a lot less fun for other players who are stuck with their normal tools.

Answer 5

A player can't hang someone from a tree branch over multiple turns using Thorn Whip. The answer by MikeQ clearly explains why not in the 1st and 3rd steps of casting the spell on a target.

But there's another way this could have gone.

I have to assume that you are talking about an attempt by the player to perform a lethal hanging, since the player was trying to have Thorn Whip wrap around the NPC's neck.

Hanging is a method of execution, designed to cause death very efficiently via sudden tension on the rope around the victim's neck, causing the neck to snap, which breaks the spine, and often severs or catastrophically damages the spinal cord. In real life, this was managed historically by having some sort of platform (wooden gallows, a bucket, a chair, a horse, etc.) for the victim to stand on while the noose was tightened around the neck, and then the platform would be removed.

The standard method is to have the victim fall (or more simply, move away from the fixed end of the rope) at least the length of their height in order to maximize the likelihood of an immediate death. Otherwise, the victim may survive and asphyxiate over a span of up to several minutes.

• See this 2007 Associated Press article describing the process and its methodology.

As MikeQ's answer also states, you're the DM here, so you have ultimate say in when to bend the rules toward the direction of fun. The 2nd step in MikeQ's description of events mentions correctly that the spell does not specify how Thorn Whip wraps around a target to pull them toward the player. This is where creativity and 'rule of cool' comes into play in a homebrew game to trump RAW:

If the player wants to target an NPC's neck with Thorn Whip, you can let that happen. This is the very common kind of scenario where the DM should allow the player to roll to see if they are able to accomplish something unique or creative. How you run the check is up to you:

• you could require the player to hit two separate DCs: one to hit the NPC (or for the NPC to meet the spell save), and a higher one to see if they can aim the Thorn Whip well enough to have it wrap around the target's neck.
• you could have a passive spellcasting skill check -- if the player's Wisdom or Intelligence or Charisma is high enough, they're able to target the spell that quickly.
• you could simply rule that, due to the element of surprise or the fact that the player is hidden, they are able to cast the spell accurately enough to do this.
• etc.

The key factor is that the player doesn't need to hang the NPC for multiple turns. That's not the point of hanging someone.

This is the bit that the other answers, thus far, haven't touched on:

If the player is able to wrap around the NPC's neck and pull him up (toward the player) in an instantaneous duration (which at the very least we can say doesn't take longer than 6 seconds, e.g. 1 turn), then the vine created by Thorn Whip would almost certainly cause a classic Hangman's fracture, which would cause the NPC to immediately go Unconscious, and their airway would be blocked by both this fracture and by the squeezing of the vine around the Carotid arteries. Additionally, as mentioned above, this often causes paralysis due to damage to the spinal cord.

Now, after the spell ends, the target would drop 10 feet, take 1d6 fall damage, and (most likely) no longer be Unconscious. However, the following things would be true at this point:

• they'd take 2d6 damage:
  • 1d6 for the Cantrip (or more if you're a high enough level)
  • 1d6 for the fall of 10 feet
• they'd be on the ground, prone, and would not be holding anything in their hands due to Unconscious conditions (including weapons, shields, etc.)
• their neck would be broken
• depending on how you rule it based on the above information, the NPC would also be also Paralyzed

At this point, the NPC might as well be dead. Even if he somehow survived, he'd certainly be no immediate threat to the party.

All of this only requires one turn to happen instead of several. This point has an added benefit when compared to your description of the player's attempted scenario:

In a game where I am DMing, if the player is hanging by a vine or rope for multiple turns in order to try and choke out an NPC at the other end of that vine/rope, I would rule that the player is 'voluntarily' Restrained; they can't move, and they can't use their hands for anything other than hanging onto the vine/rope.

This makes the dangling player an ideal target for enemies to attack if any of them can see and/or reach the player, as attack rolls against a Restrained target have advantage.

It's not really how the condition is supposed to work, but I'd probably offer the player an option upon being attacked to use their Reaction to try and dodge an incoming attack at the cost of letting go of the vine/rope. And in that event, if the player is at least 10 feet up, they'd still have to roll for fall damage, too.