The Bounty Hunters
Major differences with the d20 system
Wounds vs. HP
Characters don’t have a positive number of hit points which go down every time they are damaged. (Although armor works like traditional HP. More about that later.) Instead, players keep track of their wounds score, which starts at zero and increases every time a player takes damage. For example, if you are hit and take five damage, your wounds score increases from zero to five. Flesh wounds are very bad in this system. You subtract your wounds score from every roll you make, except damage rolls. Also, there is no instant healing. Example: You have a wounds score of five. You attack with your sword against some target which would normally require a roll of 13 to hit. But with your wounds, you will subtract five from your roll, so you need to roll an 18. Say you succeed. You then make a normal damage roll. So can you just keep taking hits forever while your rolls get weaker and weaker without ever dying? No. Characters can try for crippling and killing blows, which become easier to make as the other character gets weaker.
Armor makes it more difficult for enemies to hit you, as in regular D&D, and it also functions as hit points. Basically, when an enemy attacks you it can miss completely, damage your armor, or inflict a wound. Example: You have chain mail on, which provides +5 defense and has 50 hp. You have no other defensive bonuses. (Baseline defense is 10, just like in regular D&D). An enemy attacks you. If he rolls 10 or lower, he misses completely. If he rolls between 11 and 15, he damages your armor. Say he rolls an 8 for damage. Your chain mail has 42 hp left. If he had rolled a 16 or higher, he would have inflicted 8 points of wounds.
In this system, you use your weapons as a defense. Once per round per weapon, you can attempt to parry an attack by making an opposed attack roll.
Example: You have a sword. An enemy attacks you with his own sword and you attempt to parry. If you roll higher than him, you block his attack with no damage to you. If he rolls higher, you then compare his roll to your defense score as above. He may miss, damage your armor, or inflict a wound. Then, a second enemy attacks you. Sadly, you are out of parries for this round. If you had a shield you could attempt to block the second attack.
Focus and Tag
If you attack an enemy, your defense and parry against other enemies are at -2 until your next turn.
If you attack an enemy with a melee weapon, its attacks against other characters take a -2 penalty until your next turn.
Minions and Ganging Up
The parry and tag mechanisms combined mean that its very dangerous to fight multiple enemies at once. When fighting solo against four enemies, you subtract 6 from your attack roll. At the same time, you can only parry two of their attacks at most. The others are likely to whittle down your armor while you struggle to land a single hit. If you are much more powerful than than the monsters you are likely to win anyways, but unlike in regular D&D a high level fighter cannot kill hundreds of low level monsters without taking a hit.