Velocity of incoming attack?

[Anaraxes]

Originally Posted by Kromm

Evasive movement would automatically give you a penalty to attack that turn

I'd try something along the lines of making this a scale, -4 to +4 or maybe a bit more, and use this "Evasiveness" or "Aggressiveness" setting to replace the set of graduated attack maneuvers (All-out Attack, Committed, regular, Defensive Attack, All-out D). Aggressiveness adds to your attack skill but subtracts from your defense. The bonus applies to melee as well as ranged. "Dodge" isn't an "active" defense, but it's always available as the last recourse to see if your evasive movement saves you if you don't take an active defense.

[Andreas]

Velocity really does make a huge difference. While it is not entirely imporssible to dodge the line of aim from a gun, it is far harder to do than dodging an arrow moving at reasonable velocities. Distance to the origin of the attack also matters a lot. For example it is possible to dodge a supersonic bullet from a sniper, if the sniper is very far away and you are watching for the muzzle flash with a pair of binoculars, so the single most relevant number should be how much time passes after you spot or predict the attack.

The size of this time would determine a penalty or bonus to your dodge roll. There should also be some sort of evasive moment you could use to make it harder to hit you with attacks as described in Krom's post. This approach makes it quite straightforward to determine how difficult it is to avoid the attacks of speedsters. Divide the time you have to react to their attacks by their level of ATR. It also makes it rather easy to directly implement the effect of things like a combat precognition advantage. Add a constant amount of time for all attacks.

[Ji ji]

This has actually been debated and there is wide agreement that is not realistic.
Then you can choose if you are fine with a more cinematic/schematic/whatever approach, or if you want to improve realism with optional/home rules.