The state of being subtle, or not easy to notice or understand.
Subtility can make people think of things that are not obvious or that need careful thought.
Examples:
The subtility of her plan was impressive.
There is a subtility to his humor that not everyone understands.
The subtility of the painting's message was lost on most people.
The subtility of the magic trick amazed the audience.
The subtility of the code made it hard to crack.
The subtility of the flavors in the dish surprised me.