Alternate for Defence

Here's my idea.

In stead of passive defence, active defence.

How does it work?

Simple, instead of adding 10 to the defence number, the defender instead rolls whatever skill is appropriate (Armed, unarmed) vs the attacker's result. Of course they add their Nim mod.

The attacker needs to score a minimum of 10 for it to be a successful attack.

Alternately the defender can choose to block/parry or dodge the attack so long as they;

a] have an action left

b] declared a defensive action before initiative

Was this an alternate rule in Star Trek or LotR? I was talking with Mr. Burke and he seemed to think it was but couldn't remember off the top of his head.