Hero Dice
Hero Dice are a pool of d6s available to every player character (not NPCs or monsters) that can be used to influence the outcome of any Trial they make. Your pool size equals your Prowess + your character’s level. A character starting at level 1 will have 2 Hero Dice; a character at level 7 will have 10.
On any Trial, after the dice are rolled and all modifiers are applied, but before the GM declares the outcome, you may expend and roll any number of Hero Dice from your pool. Add the total of those d6s to your Trial result. This allows you to push a miss into a hit, or a Normal Success into a Strong or Devastating one.
If a feature, effect, or spell modifies the total number of Hero Dice in your pool, it can never set it lower than two.
Separate from Edge and Strain
Hero Dice are separate from Edge and Strain. Edge changes which d10s you keep from your base 2d10 roll; Hero Dice add d6s on top of the final total. A character with Edge who also spends Hero Dice benefits from both — they are different layers of the same roll.
At the table, this distinction is physical: your base roll is d10s, your heroic push is d6s. Different dice, different pool, different decision.
A Narrative Focus
Hero Dice are meant to influence the narrative of a character’s actions throughout a session. Because of this, you regain all expended Hero Dice at the start of a session, not when your character finishes a Rest or Recovery. Additionally, the GM may award or restore Hero Dice to your pool during a session — doing so is entirely at their discretion. Any bonus dice awarded this way are lost at the start of the next session.