Dodge - Active or Passive?

[Gollum]

Originally Posted by gilbertocarlos

Wait a minute, if Dodge is reflexes, why is it influenced by DX and HT, but not by Per?

Exactly for the same reason than Parry, Block, Shortsword, Driving and Piloting are based on DX though, in reality, they obviously require a lot of perception...

DX includes some perception. It is not only agility, flexibility, quickness, balance and fine motor ability. It is general adaptation of the body to the surrounding, which includes perception and even one kind of intelligence: bodily/kinesthetic intelligence.
http://en.wikipedia.org/wiki/Theory_..._intelligences

What is the stat for reflexes in GURPS? Basic speed.

"Basic Speed is a measure of your reflexes and general physical quickness." (GURPS Lite, page 6)

Does it require Perception? No. Only DX and HT...

Why? Because it is Reflexes against a perceived thing. Most of the time, you only roll against that stat because it is obvious than you perceived the source of your reaction. But some other times, the GM will require a Perception roll first.

Exactly as for Dodge. The GM may require a Perception roll first to see if you are aware of the attack.