It was important to me that the feel of combat be right. I remember playing a simple card game many years ago on a rainy evening on the Burmese border. The game consisted of two players alternately laying cards and keeping track of the total value of the cards laid. The person who took the total over 101 was the loser. Certain cards would decrease the total, or jump it direct to 100. It was a compelling yet simple game which felt more like a combat than any so-called combat I’d ever experienced in a roleplaying game.
I wanted to combat in Call of Cthulhu to have the feel that both sides are struggling against one-another, both rolling dice every time. The way I see it, your character is trying to hurt mine. I must choose either to dodge (to avoid the blow altogether), or to engage with you, trying to land a blow of my own whilst avoiding yours.
That’s how the new combat system works. Every time you are the target of an attack you choose; either you attempt to dodge or you fight back. Dodging is a good option because you’re less likely to be hit, but you won’t hurt your opponent. Fighting back is a good option because you might deliver damage to your opponent, but (chances are) you’re more likely to get hurt in the process.