I've been wondering this for awhile.. I was playing around on my f2p noob with 1 agility, and I found a group of level 100+ pkers. I decided to tag along and kill people my level... So we are going north, all 100% energy, I have about 20kg energery and they have like full rune, full lobs, etc so Im guessing they had about 45+. So we are all roaming by greaters, and we see a few guys. We all run after them and kill at about the mine (Not me, too weak). I come running after gasping for air "How much *pant* energy do you have *Pant*?" They all start naming 75, 80, all those high percentages. Im at 0%. So Agility affects your F2P energy?