First, does the defensive stunt take the place of your dodge action value? Or is it used to save your bacon when it's already been determined that you've been whacked? And what kind of benefits can you get from a defensive stunt? Can you do damage? Or cause impairment, like blinding or stunning, or what? Does it cost 3 shots, or just one?

Just trying to get the most out of the game...

Thanks...

There's no reason why there couldn't be reflexive actions (some of the Fu schticks work that way, in any case), and as long as you make the shot cost appropriate there's no problem. I'd say they should only be used to prevent further badness (no reducing damage or causing any harm to an opponent- unless dramatically appropriate). Think of saving throws.

Itend to work slightly differently; if there's something nasty that's about to happen I make sure the characters have an action available to do something about it. For example, if they're knocked of a bridge their next acton will find them within grasping distance of the rail. After all, sequences are nominally 3 seconds long, and you can't fall far in half a second.

As long as you make sure that defensive stunts don't hose the active dodge rules of give an unfair advantage, run it how you will.

What happens if you fail the defensive stunt? Do you still get your normal dodge value? What happens if you make the stunt? Are your opponent's shots wasted? Can they pick another target?

Thanks...

UNLESS the attempt was a Way Awful Failure, in which case I ususually describe something ridiculously embarrassing for the hero, but again not fatal. (Perhaps a Fumble on a defensive stunt simply sets that PC back an extra shot.)

If a PC -makes- a stunt roll, then I usually rule that the opponents' shots are wasted, yes. That's the benefit of trying stunts.