The Magic Circle spell description says:
- The creature can't willingly enter the cylinder by nonmagical means. If the creature tries to use teleportation or interplanar travel to do so, it must first succeed on a Charisma saving throw.
- The creature has disadvantage on attack rolls against targets within the cylinder.
- Targets within the cylinder can't be charmed, frightened, or possessed by the creature.
What happens after a creature of the chosen type penetrates my Magic Circle? Does a character lose the other protections of the Circle for that creature?
I had always assumed no. I thought the creature could then try to knock or drag them out of the circle, but those attempts would still be made at disadvantage. And as long as they remained in the cylinder the character would still be immune to the creature's charm, frighten or possession attempts.
An answer to a question about an inverted Magic Circle made me doubt my understanding. It made it sound that it is the barrier (the surface of the cylinder) that provides those defenses not just the state of being inside the field defined by the cylinder. I think my confusion lies in that the rules text doesn't say something like, "As long as the creature is outside the circle it has disadvantage..." or "...can't be charmed, frightened, or possessed by the creature as long as it is outside the circle." The only criteria I see is that the targets have to be in the cylinder, nothing about where the creature is.