Ok, so.... Do simple.... Take basic system; know to use it for (how to implement user interface). Give basic choices for situations you put people in. Record what happened for your reference....
I'd do one "main character" on a storyline, combat focus beginning. Situational based with choices (buttons you can press), to start. Good interface requires good writing most teachers don't know, can't teach, and wouldn't recognize. Both educated and uneducated people routinely botch things....
For those who don't know, most real fights last 30 seconds, maybe a minute, rarely a minute and a half. Hobbes knew: life is short and brutal, so are these:
"You see the small leather glad red goblin's sword over its shield. You brace for its charge, stepping out of the way, and turn to face it. It screams and charges again; your swords catch; it's shield rim fails to bash you; your armored kick hits it shin; it yelps and jumps back. You pursue, armor catching the shield bash, sword nicking its dominant hand, and fist grasping riping away & flinging aside its shield. It charges sword in both hands upswung cutting your leg a bit, as your sword slashes its face. Blood in its eyes, it feels but never sees your sword it its neck. It lays there bleeding out and a small bit of blood comes from your outer leg."
Multiple combat rounds (about 7 under most games) in a single paragraph.
That is dense, detailed writing describing a deathmatch. The player(s) may have some input, while acknowledging inherent chaos. Given three choices, the player chose a defensive stance (with bonuses), counterattack with disarm if possible (here shield happened), followed by an aggressive strike. It's more real that way, because you can't determine what your enemy does only what you do in a given situation. Operationally, this gives three data points of input, from the player as processed by the foe. Other factors including environmental, tactical, etc. Basically, perception matters, as does common sense. Life's an equation, influence the factors you can for better probabilities.
There may be other options, but without an environment breakdown or any context, that's the best possible.
Make any sense?