I am looking to build a sorcerer focused on the Metamagia of the Twin Spell and what spells I can use with it (for example, Hurry!).
Looking around, I found myself these tweets from Jeremy Crawford declaring that the dragon breath The spell cannot be twinned. As I understand it, this is because its effects can harm several people. Contrary to spells like rush, which can also damage multiple targets with the additional attack, this spell explicitly sets the second set of targets.
the dragon breath the spell says (XGtE, p. 154):
Until the spell is over, the creature can use an action to exhale energy of the chosen type in a 15-foot cone. Each creature in that area must perform a Dexterity save throw, taking 3d6 damage of the chosen type in a failed save, or half damage in a successful one.
I was wondering what other spells on my list are affected by this, and I found crown of madness, whose description states the following (PHB, p. 229):
The enchanted target must use its action before moving in each of its turns to perform a melee attack against a creature other than itself that you choose mentally.
So this spell also has a second set of explicit objectives in its description. This led me to this question:
can crown of madness be twinned?
Note: While researching this, I found a similar question in RPG.SE about twinning the enemies abound spell out. I think my question is different, because in crown of madness, the spellcaster chooses the other creature that is damaged, so it seems more a direct target of the spell than in enemies abound, which simply makes the creature perceive all creatures as enemies. So I think this is not a duplicate.