Do you only block attacks that would hit?

[J. Strange]

If a character chooses to block, does he only make his attack roll against attacks that would hit (i.e. rolls higher than his Defense)? I would think so.

[Steve Kenson]

If a character chooses to block, does he only make his attack roll against attacks that would hit (i.e. rolls higher than his Defense)? I would think so.

You would think correctly. Yes, you only need to roll to block attacks that would actually hit your defense.