An essay on another blog a few weeks back reminded me that I always wanted to revise critical hits to make them more interesting. When considering ways to do this, I remembered how much I loved the old Battletech critical hit system. In that system if a hit was critical a roll determined which specific part of the battlemech (giant robot) was damaged and it noted how that hit affected the battlemech. Here’s a new system along those lines for OGL 3.5 style games that should be easily adaptable to other systems:
A critical hit is determined as per the existing game rules. In OGL 3.5, a natural roll of “20” on a d20 to hit means there is a critical threat. (With some weapons a 19 or 18 could also be critical threats.) Another d20 is rolled and if that roll would hit the opponent, the hit is critical. In the core rules system the damage would be doubled or tripled depending on the weapon.
In this system, the critical threat is confirmed in the same way, but the damage isn’t automatically doubled or tripled. Instead, roll 2d6 and check the following chart: (Note: in most vases the target suffers these effects instead of extra damage.)
12: The target suffers a concussion and is knocked out if he fails a fortitude saving throw (DC 12+ the attackers base attack bonus). He can try to regain consciousness every five minutes by making the same fortitude saving throw. If the target succeeds the original saving throw he isn’t knocked out, but he suffers a critical hit as per the normal rules. (Double of triple damage, depending on the weapon.)
11-10: Broken Arm. The target’s weapon arm (or arm closest/most involved in combat) is broken. The target suffers a -4 to attack with the arm until healed. He also has a 20% chance of spell failure if casting any spells with a somatic component until healed. Whatever the target was holding in that hand is also dropped.
9: Shattered hand. The target’s weapon hand (or hand closest/most involved in combat) is smashed or deeply cut. The target suffers a -4 to attack with the hand until healed. He also has a 20% chance of spell failure if casting any spells with a somatic component until healed. Whatever the target was holding in that hand is also dropped.
8: Punctured/smashed lung. The target’s constitution is halved until healed.
7: The damage is simply doubled or tripled, depending on the weapon as per the core rules.
6: Severed artery. The target suffers two points of damage per round until he can be bandaged. (See the healing skill.)
5: Smashed ankle. The target’s ankle is crushed or deeply cut. His movement is lowered by 5feet/round and his dexterity is lowered by 2 points until healed.
4-3: Smashed leg. The target’s leg is crushed or deeply cut. His movement is lowered by 5feet/round and his dexterity is lowered by 2 points until healed.
2 Pierced/Smashed eye. The target’s eye is damaged causing a -1 to hit penalty (-4 with ranged attacks) until healed.
If a target doesn’t have the body part mentioned, the gamemaster should use his best judgement to determine the creature’s equivalent body part or else re-roll the critical hit effect.
A few of the above mention that the effects last until the target is healed. In the case of a severed artery, this healing is the simple healing skill. But in all other cases, a cure moderate wounds (or more powerful) spell must be used on the target. The magical effect must be solely directed to the injury. (In other words the spell will not restore normal hit points unless the spell is recast.)
As a separate change, I find that a 1-in-20 chance (or more) for an automatic hit is a little too high. So I make to-hit rolls “open-ended”. If a player rolls a 20, he rolls again and that is added to the 20. If he amazingly rolls a 20 again, he can add another roll. In this way, a character with an low attack bonus could still hit a creature with a very high armor class, but he doesn’t have the 5% chance to automatically hit as the core rules allow for a natural 20. The natural 20 does still entitle him to a critical threat, but he must roll a 20 on his confirming d20 roll, then roll high enough on his second roll that the 20 + his second roll would hit the target.
But even if you prefer the core rules for determining criticals, you can use the rest of this critical effects system.