As I was looking through some legendary creatures, I had a thought. Most legendary creatures get three Legendary Resistances per day, which they can use to automatically succeed on a saving throw.
A Concentration check is technically a Constitution saving throw, so does that mean that a creature can use a Legendary Resistance to automatically pass a Concentration check, or is it not considered a saving throw?
Best Answer
Yes, it is a Constitution Saving Throw
PHB p.203: Constitution, Taking damage
Yes, Legendary Resistance Would Work
MM p.48, Demilich stat block.
A legendary creature could use legendary resistance to succeed, if it had uses left and it wasn't saving it for something else.