Modify a Hero Die by 1: This Free Action is listed on each Hero Mat. During any Skill Check, spend 2 to change the die face result of a single Hero Die (not the Enemy Die) by 1. You can do this as many times as you have to spend. For example, you can change a 3 to a +2. This cannot change a die face above 6, below 1, or go from 6 to 1 or from 1 to 6.
This Free Action can only be performed during a Skill Check, and it's the only Free Action you can perform in the middle of another Action (Heroic or Free). However, if you started your turn Unconscious, you CANNOT perform Modify a Hero Die by 1 during possible Skill Checks during that turn.