During our last session, we were fighting two bosses, who I believe were demons. They had the ability to disappear, and travel around. The first one vanished, and according the DM left the fight completely. We had been doing some solid damage to the other, so being a Necromancer Wizard, I cast the cantrip Chill Touch.
You create a ghostly, skeletal hand in the space of a creature within range. Make a ranged spell attack against the creature to assail it with the chill of the grave. On a hit, the target takes 1d8 necrotic damage, and it can't regain hit points until the start of your next turn. Until then, the hand clings to the target.
My ranged attack was successful, so the hand remained holding the boss. On her next turn, the DM had it vanish, and leave the battle as well, giving us victory. However, I tried to argue that the hand would have been able to prevent it from vanishing as I had a solid grip on it. The creatures don't teleport, they just turn invisible and move. We didn't see anything in the handbooks, so I deferred to the DM's ruling. However, we both were curious if we got the ruling correct. Is there something that we missed? Does the hand give me the ability to prevent that boss from escaping, or even a regular enemy from moving?
A couple other points
- Not remembering what race the enemy was: It was only taking full damage from silver weapons, and this necrotic damage was the only spell type that it did not take half damage, or none at all. Also, it was not an undead target, as would be affected by the rest of the above cantrip.
- We're only level 4, and I'm not sure if the spell would get more powerful at later levels.