What it does
Fear is an evasion ability that restricts how a creature can be blocked. A creature with fear can only be blocked by artifact creatures and/or creatures that are black. Everything else simply can't block it, making it a reliable way to push through damage.
The common mistake is thinking fear requires both qualities. It's "artifact OR black" — a colorless artifact creature blocks it, and so does a black creature regardless of whether it's an artifact. A black artifact creature obviously works too. Fear only affects blocking, not anything else; the creature can still be targeted, killed, or otherwise interacted with normally.
In Commander, fear is weaker than it looks because black is extremely common across four-player tables, so someone often has a legal blocker. It's largely been replaced by intimidate and menace, but it still enables combat damage triggers and commander damage in the right metagame.













