Yes, I think it's quite possible to make something turn based, or even real time, though that would be trickier. You'll likely be working with values. You can assign those to characters, as you may be aware. Just a disclaimer: I haven't actually done something like this before, I'm just giving you what I think would work.
Say your player character is labeled "Hero." Create a value "HeroHealth" under its value tab. Set the current value to 100, the minimum to 0 and the maximum to 100.
You could also have one called "HeroChanceToHit," "HeroDefense," "HeroStrength." These you could set between 1 and 10, just to make things simple. Also create the value "HeroSwing." You don't need to bother setting a number for this.
Create a character "Troll," and create values for it like you have for "Hero."
So, let's say you want to have the player try to hit the troll with his sword. For simplicities' sake, that will just be a left click on the troll. Create an action under the Troll's action tab, and set the Execution type to "Left Click" under "Execute Immediately."
So let's see if the hero successfully hits the troll. Back to the Troll's action tab and the left click option. Use the action part "Set random value," designate "HeroSwing" and set the min and max to 0-5.
Next, use the "Set value" action part. In the first box, pick "HeroSwing," set operator to +, then the other value "HeroChanceToHit." Say you set "HeroChanceToHit" to 5 earlier, and the "HeroSwing" was set to 4 by "Set random value." So "HeroSwing" is now 9 based on hit skill and a random element.
Now use the "If value." First box is "HeroSwing," make the operator ">" and set the final box as "TrollDefense" which let's say you chose to be 8 earlier. "HeroSwing" is greater than "TrollDefense," so the hit connects.
Let's use "HeroSwing" again to determine how much damage is dealt to the troll. Set a random number to it again, let's say 1-20 this time, then add "HeroStrength" to it. Use "set value" again: "TrollHealth" - (minus) "HeroSwing." And the troll takes this amount of damage. End the "if" section with an "end if," obviously.
So use your own numbers, maths, and stat systems, but this is how I'd set this up at a basic level. If you're doing something real time, you can include response actions to attacks such as dodging or parrying, which would possibly increase "HeroDefense" for a certain amount of time. Something that uses timed events like that will likely require some scripting, though.
Anyway, I hope this was more or less what you were looking for, and good luck on your game.