Some thoughts on attack and defense
In most combat systems these two things are assumed to be exclusive to each other. When someone makes an attack action, there is either some passive defensive stat for the target, or the defender makes a defense action/reaction of some sort, trying to negate the attack. Or there is no defense and just an exchange of attack actions dealing damage turn by turn.
This seems a natural way to portray combat in a turn-based game, but I think it is actually very... unnatural. And it is wasted potential. Because in different kinds of real-life combat, the best defense is offense. Opponents defend themselves by attacking each other. You are not just standing before your enemy passively parrying; your weapon is both an obstacle for their blows as well as a constant threat pointed towards their body. Each parry might end up being a blow that injured or killed the enemy. And there are mutual hits. In many instances in real life they are as common as one-sided hits.
Systems where you wait for your turn to make an attack, and in the meantime may only watch if your opponent hits you, or else may only roll to negate their attack, give an absolutely different feeling. They don't allow for the intuitive defensive offense, and mutual hits are impossible. They also cause these regular pauses of no engagement in the game.
What might be a far more effective solution would be some sort of a fight action, serving as both attack and defense. Two opponents could use a fight action on each other simultaneously, and their rolls would determine if anyone hit the other first (and whether or not that hit was enough to stop oneself from being hit immediately after). Of course, there would always be the option of dodging, which is running away from enemy's attacks with no offensive potential (and unless limited by terrain, dodging should be easy).
I don't think such an approach is sufficiently explored or as popular as it deserves. To me it seems more engaging, quicker, and closer to how it works in reality.