Masterminds are extremely intelligent villains and are characterized by a clever personality in which they will plan things to amazing lengths and always have a backup plan in mind. They are may often be non-action or even weaklings, but they should not be underestimated, as they can be extremely difficult to catch or defeat due to their incredibly complex schemes. They are usually referred to as "the brain behind it all" and just like Master Manipulators, they rarely show themselves directly towards their enemy.

The only way a Mastermind can be defeated is if the hero or another character (whether evil or not) finds a way to exploit their arrogance or egotism, if they are of similar intelligence or by a huge stroke of luck.

To qualify as a Mastermind, such characters have to be rarely caught off-guard and must have a Plan B, C, or D to fall back on should their original plan be foiled. They are the polar opposites of Dimwits, who are either proven to be rather stupid, and can seldom (or never) make any smart decision. Of course, they are rarely Incompetent. The only way a Mastermind could be incompetent would be a comical character, whose failures are played for laughs. Schemers tend to be very intelligent and it's possible for them to be incompetent.

Also, manipulative machiavellis, or skilled tricksters are not necessarily masterminds unless they meet the aforementioned criteria, and proved to be successful in most of their plans.