I have a lot of times that i fight the thugs that i dont deal any damage. Is this random?

No, it's based on your ability To Hit dice (via your weapon and your stats), and the enemy's stats (armour rating, dodge, speed, dexterity etc.), and darkness also factors in.

Thanks so i need to higher up my dex?

No, it's not that simple. As I said, your chance 'To Hit' is on the roll of a dice (it's called a 'To Hit' dice). The chance To Hit depends on a lot of things: Strength, Dexterity, Speed, Dodge, weapon quality (+1 weapons is better than basic; +2 weapon is better than +1), darkness can obscure a target and make it much harder To Hit, and so on. So it's not just a case of upping your Dex.

Agreed. if you want any more information all of it can be found here for both games. http://www.basiliskgames.com/forums/index.php?sid=c1fedbcd4a2dd991031bea1bac77577d

Ah with other words it uses pen and paper concept the game throws a dice and ad the to hit bonus to it thats why I miss a lot I always throw bad with my dnd sessions

Dexterity is usually only for book 2 for piercing weapons. If you are a bow/marksman, go with dexterity, if you are a fighter, go with either strength, endurance or speed as they affect your durability and your damage. A good combo is strength/endurance or strength/speed, speed/endurance. The way you get around not being able to hit enemies is by investing at least 2 points in a weapon skill per lvl for melee.

If you want to use dexterity and still do melee weapons go (2) dexterity per lvl with (1) into endurance each lvl as well. That way your not a glass cannon and still can take hits.

I found an amulet that gives + 3 to hit so now my survival change has inncreased a little