Every Game in The Contract must be deadly, and so combat-- the easiest way of achieving deadliness-- occurs almost every Game. The outcome of Combat is determined less by the raw stats of those involved and more by the circumstances of the fight. Running headfirst into every encounter will result in serious injury and death. Contractors should strive to be creative and create other advantages such as an ambush, a numbers advantage, a setting advantage, etc. Combat has no direct reward (such as Exp), and so avoiding unnecessary combat is a wise and successful strategy.
Players do not need to fully understand these rules before playing, but GMs must know them before they GM a Game.