attack without challenge

[Merlin]

Why sometimes other players had attack me whithout challenge?
It's not duel but murder. For me i cannot attack any player?
 How programme my mouse for aiming and fighting in one click (my mouse is a 7 buttons mouse)
Thank you very much
Merlin

[Karyuu]

If you are in a certain room within the Arena (I believe it's marked by a shield), you're in a free PvP zone. Players can also attack each other without requesting confirmation if they are in a guild war. You can try look around in the Options window in the game to see if you can put your mouse to better use, but chances are it's not going to be put to its maximum use here.

[Nikodemus]

But if everyday hundreds (yay) of gladiators and mercenaries are killed in the corridors of arena, this isn't murder? ;P But noone will be punished for mass murder? ;P

As for attacking with one key, you don't really use mouse for it.
You need to make macro /clear target; /target nearest player; /attack 1; Then assing a key for it and you are done.