One of the fun mechanics that power Fantasy Craft is action dice. Your character begins each session with a set number of these and you get to spend them on things that make your character look even more awesome than they already are, and then rewarded for good ideas, nice roleplaying, and some character options can grant you action dice in certain situations.
Here's the list of things you can spend your action dice on:
1. BOOST A DIE ROLL
A character may spend 1 action die to boost each attack check, skill check, Knowledge check, or saving throw he makes. He may also spend 1 action die to boost each of his lethal, stress, or subdual damage results. The choice to boost may be made after the dice are rolled, so long as the outcome has not yet been described.
When boosting, an action die “explodes” when it rolls the highest natural number possible (e.g. a 6 on a d6). The player rolls the action die again, adding the new result to the previous one. An action die may explode multiple times, resulting in an extremely high boost.
An action die may only be spent to boost a check or result when dice are rolled. Thus, a character may not boost a skill check when he takes 10 or 20.
2. BOOST YOUR DEFENSE
At the start of any combat round, a character may spend 1 action die to boost his Defense by 2 for a number of rounds equal to the die’s result. This action die may explode as described in Option 1. A character may only benefit from one action die boost to Defense at any time and the result of a new die spent to boost Defense replaces the old one, even if it’s lower.
3. ACTIVATE A THREAT
When a character scores a threat with an attack or skill check, he may spend 1 or more action dice to activate it as a critical hit or success (see pages 207 and 65, respectively). The choice to activate must be made before additional (e.g. damage) dice are rolled and/or the outcome is described.
4. ACTIVATE AN OPPONENT’S ERROR
When an opponent within a character’s line of sight suffers an error with an attack or skill check, the character may spend 1 or more action dice to activate it as a critical miss or failure (see pages 208 and 65). The choice to activate must be made before additional dice are rolled and/or the outcome is described.
5. HEAL YOUR CHARACTER
Outside combat, a special character may spend and roll any number of action dice to regain vitality or wounds. For each action die spent, the character regains an amount of vitality equal to the action die’s result and 2 wounds.
During combat, a character must take a Refresh action before he can spend an action die to regain vitality or wounds.
An unconscious character may not spend action dice to heal.