If someone is suffering the Grappled condition and is then moved by another means what happens to the person providing the Grappled effect?
In a situation the fighter had grappled with the scary bird monster, another character who was "behind" the fighter casts Lightning Lure. The creature failed its Strength save and so was pulled towards the caster. We allowed that the fighter would pivot to allow the Lightning Lure to pull the creature.
Was this a fair reading of the rules? As Lightning Lure only has a range of 15' it seemed that (if using squares) that it would go from:
| M | F | | | C |
to
| | F | M | | C |
(Key: Monster, Fighter, Caster.)
I don't think there are additional considerations for Thorn Whip's longer range, but answers could include any such details.
Best Answer
The rules on Grappled condition seem to answer the first part of your question :
So that's what happens to the person providing the grappled effect: he loses it's grapple if the creature is taken out of his reach.
As for the second part, here's what Lightning Lure does :
Unless I'm wrong with square count, your caster seems too far away to reach the monster (space 1 = 5' from him, space 2 = 10', fighter = 15' and monster = 20'), which is over the cantrip's range.
Now if you placed the caster 5 feet closer, the spell would work. It would hurl the creature over the fighter and 10' (or 2 squares) towards the caster, but still in reach of the grappler, thus not ending the grappled condition in the process.
On a grid, the positions would change from [monster|fighter|space|caster] to [space|fighter|monster|caster].