Basic Action Super Heroes!

What do you think of the following rule?

Targets that are unable to defend themselves or react to danger (especially immobilized, dazed or surprised targets) are far more vulnerable. Firstly their physical defense is 0 as long as they are helpless. Also the result of the to hit roll is added to the damage done by the attack.

Considering the all-or-nothing nature of those powers, that pretty much guarantees a character with a Mind of 1 to be automatically out of the combat. A tad bit too powerful, IMO.

For comparison, that is what the rules state for villains:

A Villain who is Immobilized, Dazed, trapped inside a Force-Field or under a similar effect, with no hope to escape (or way to avoid being put back into that effect as soon as s/he does escape) should be considered defeated.

I think giving someone the Major Advantage ruling vs. someone immobilized, dazed etc.... pretty much covers it. An extra +1 multiplier OR +3 to the roll.... and that way no extra rule has to come into play. It is already covered.

I came up with that rule because I like the 100 hitpoints in a battle. The high number usually ensures an interesting battle that is not over after one round (or two). On the other hand I miss the danger for strong supers that you find in nearly every comic coming from considerably weaker enemies. If a strong mutant or other superhero does not extpect an attack a thug with an automatic can be a real threat. I like it that this is possible. It is not though using the 100 hitpoints system folowing the original rules. There a fairly ok soak or physical defense make sure that even surprise-attacks of a "normal" foe do not do severe damage. Once a super can retaliate against such an opponent the battle is over (this is ok for me).
I think with the above rule you ensure that Spidey has to fear a gun or the Human Torch a thug hitting him with a beer bottle...
Another rule to represent that could be:

As a called shot an attacker can try to knock his opponent unconscious. He can do so barehanded or with any blunt wepon. He does no damage with the attack. If the attacker hits by 10 or more he rolls damage normally. The opponent then rolls Brawn. If the attacker beats the opponent, the latter is dazed and may recover as per the the Dazed rules rolling Brawn instead of Mind. If the damage roll is 10+ higher than the opponent's Brawn roll, the opoonent is knocked unconsious.

I don't see how that's a valid comparison? Your rule is a combat penalty for being immobilised/ dazed/ surprised, the other is a guide for when combat is over.

Personally I'd give a -4 to defence rolls for being surprised/dazed rather than a 0 defence, as per the rules for Immobilise.

An Immobilized opponent has a Major Hindrance to Defense rolls