There are also immediate effects of being wounded. You might go into shock and be out of the fight. A hit to your arm might cause you to drop what you hold in that hand, or an impact on your legs might cause you to stumble and fall. In the end, a lucky swing of a sword or axe could decapitate an enemy in one stroke.
The actual mechanic is simple. You declare you are striking at a foe with a weapon. Your target chooses to Block, Counterstrike, Dodge, or Ignore. Each side rolls against the appropriate skill (except for Ignore) and compares their result (Critical or Moderates success or failure) to see the result. Every weapon has three aspects, Blunt, Edge, and Point, with a number describing their impact. For example, a spear has 4/-/7 meaning it is best used as a thrusting weapon, although you could use it as a quarterstaff in a pinch.
Armor is also rated for its defense against B/E/P, can be layered (within reason), and covers specific hit areas. So let us assume that a person wielding a spear gets moderate success against an enemy who rolls a mild failure to block. The result on the chart is A*1, meaning the attacker rolls 1d6 and adds it to the point aspect of his spear. I roll a 5 for 7+5=12—12 impact. A d100 roll for hit location yields a 42 for the right elbow. The target is wearing a long-sleeved leather jerkin, which gives 3 points of protection against Point attacks. So nine injury points go through.
Consulting the Injury Table, nine injury points to the elbow is a Serious 3 stab. This has several effects. Three Injury levels immediately incur a -3 on all attribute rolls and a -15% on skill rolls (-5% per injury level.) In addition, the wounded combatant must roll 1d6 for every point of his Universal Penalty, including all injury points, fatigue levels, encumbrance penalties, etc. This roll is compared to the Constitution of the combatant, and if it is higher, the wounded man goes into shock and falls unconscious. There is also a 3d6 Fumble roll against Dexterity; fail that, and the combatant drops whatever is in his right hand.
It sounds complex, but with practice, it flows very well. Many HM players roll two sets of d100s for both their to-hit and hit location rolls simultaneously to save time. As you can see, getting wounded has severe and immediate consequences, and you can be knocked out of combat by the first wound you take. Edged weapons can amputate limbs and even heads with a lucky strike, some injuries leave you bleeding to death, and you may find yourself crawling from the battlefield, dragging your useless leg behind you.
The system is fast and brutal, leaving PCs with real consequences for drawing swords. Did I mention the rules for wound infection? Yeah, you can die from that. Probably the best realistic combat system around. I like to take new players and have them do a few combats with pre-generated characters to emphasize that this is not D&D.
There are also rules for mounted combat, missile combat, and jousting. What is missing are rules for fighting in a shield wall, which is a glaring omission, as it was the most common infantry formation of the era for most nations. With the pseudo-Roman Thardic Republic and its legions as part of the setting, you would think that this would be an essential inclusion.
Next up, Gods and Magic!