I'm doing the first mission at the outposts and what I find disturbing is that the rathounds always run at me before I manage to click and shoot them. So, is there an option to initiate combat first or do you just need to to click fast?
Combat is initiated automatically once an enemy detects you. You and any enemies who see you will roll for initiative and begin moving in initiative order, which is determined by a random dice roll and the sum of agility and dexterity. Unless you have high results in both skills and/or get a high roll most of the time enemies will move first.
Other ways to get the drop on enemies include manually starting combat (by pressing enter/clicking the combat icon in the bottom right). If you do this when enemies are unaware of you (you're out of their sight range or hidden via stealth) then you will automatically win initiative. The other way is to use a combat ability out of combat, like using snipe, aimed shot, or even manually using your basic attack (available by either clicking on an enemy without an ability selected, or by manually using the basic attack ability that is bound to hotkey 1 by default. Upon executing the ability, whether it hits or not the target, they will become aware and hostile towards you and combat will start (even if you're outside of their sight/detection range).
The only reliable way to be the first person to move during combat is to use stealth, as initiative is random and even with high stats you can still lose (plus there aren't many builds which benefit from massive agility scores yet).
