Critical Hits

[Artking3]

I love the rule first seen in the Blue Rose RPG, which was later developed into the True20 rule set. But I couldn't help tinkering with the system, to incorporate features seen in other RPGs I like.

One of the changes I am making is to the critical hit rules, where each weapon has critical threat ranges and critical multipliers. The critical hit system in True20 seems both too random and too weak at the same time. +3 damage does not seem dangerous enough, so I changed it to +5 damage, as used in the Mutants & Masterminds RPG 2nd ed.

I have seen how a lucky critical hit can unduly influence a fight. A lot of fights just seem to be rolling until someone gets a critical hit. I would like skill to make more of a difference. Looking at RPGs with Margin of Success (MoS) systems, a roll above the baseline would give greater success to the task at hand. Those systems add to damage with greater Margins of Success. True20 already has DCs, which scale at multipliers of 5. I therefore made a Margin of Success scale for True20, which scale in multipliers of 5 as well.
Reading Decipher's Lord of the Rings RPG (among others), a critical hit for that system occurs on an Extraordinary Success, which is the 4th highest success, the lowest success being 0. In essence, it is the 3rd MoS for D20, which would make it a roll of 15+ (3x5) over the base roll.
For example, a opponent's Defense roll is 22. If you attack and your total attack rolls was 37 and above, you would inflict a critical hit. I was thinking you would inflict even more damage with higher MoS.
15 seems like a nice number, not too low that any mook can get a critical hit without some bonuses from surprise, yet not to high so that someone of equal skill may make it once in a while. I was thinking about 10 but that may make CHs too easy to get.

I know these changes may make the system seem a little broken, but I have made a whole list of house rules and combat options which it make more sense (including a class-less system like Mutants and MAsterminds, removal of some feats and adding of others). As it is, how does it look to other people? Too weak, too broken? All opinions and constructive criticisms are welcome. Be gentle

Edit:Changed all references to D20. This critical hit system was only designed to be used with the True20 system, where armor adds to Toughness Saves and Defence is a combat skill. As it is, you can kill an opponent without a critical hit in a single blow. This critical hit system is made so a skilled warrior can more easily kill off mooks in a single blow, while the danger of a critical hit against you makes the player rely a bit more on tactics instead of charging in and getting himself surrounded. Being surrounded by multiple attackers means a penalty to Defense (another house rule, cribbed from Game of Thrones), while several aid other rolls means bonuses to attack. All that means a skilled warrior surrounded by several attackers may get a critical hit against him because of stupidty, not because of 1 or 2 unlucky rolls.

 

[Hawken]

If you're thinking of treating the AC as basically a DC (and thus scaling by increments of 5), then how about just increasing the critical threat range by 1 point for every 5 that you exceed the AC? 15 over AC to get an auto crit seems broken, especially at higher and epic levels. This way the chances of scoring a critical hit scale with your skill but still ultimately have the randomness of and reliance on the roll of the die.

 

[Artking3]

If you're thinking of treating the AC as basically a DC (and thus scaling by increments of 5), then how about just increasing the critical threat range by 1 point for every 5 that you exceed the AC? 15 over AC to get an auto crit seems broken, especially at higher and epic levels. This way the chances of scoring a critical hit scale with your skill but still ultimately have the randomness of and reliance on the roll of the die.

True20 has a Base Defense Bonus for each class that increases at the same rate as Attack Defense Bonus, so at higher level and epic levels, the chance for a crit is still about the same between combatants of equal skill. It is not static like standard D20 AC.

Or should I make a 15 a threaten and require a second roll to confirm the crit?

 

[DJCupboard]

While I like the idea of critical damage having more to do with skill than luck, I think your system as currently designed requires too much skill to pull off. As it stands under your system as presented an 18 strength fighter with weapon focus could not score a critical hit against an average defense roll of 19 (8 from full plate, + 1 max dex bonus, + 10.5 average roll, rounded down) at all until 9th level with a roll of a natural 20. So nearly halfway through a full class progression there is a 5% chance of scoring a critical hit (discounting magic, since the armor can also be similarly counter-enchanted) and before that there is no chance. Against a maximized defense roll of 29 (8 from full plate, + 1 max dex bonus, + 20 perfect roll), there is a 5% chance of a 19th level fighter with 18 strength and weapon focus rolling a critical hit and no chance for anyone of a lower level. Which means, presuming maximized rolls, a 1st level orc fighter with an 18 constitution, maximum hit points (14 hp), full plate armor, and a 12 dexterity cannot be killed with a single blow by our example attacker wielding a long sword until 19th level (maximum non-critical damage 12) and even then only 5% of the time. Even if we give our attacker weapon specialization after 4th level, the orc can take toughness twice (as its 1st level feat and 1st fighter bonus feat), giving it a maximum starting HP of 22 and the attacker a maximum non-critical damage of 14.

I like the concept, but it needs to be adjusted for use in straight d20 to be easier without making it too easy.

~DJC~

 

[Hawken]

I did not understand it was for True20 because of this statement you had right in the middle of your post.

I therefore made a Margin of Success scale for D20, which scale in multipliers of 5 as well.

You said you made it for D20, which is quite different from True20 (I have both).

Or should I make a 15 a threaten and require a second roll to confirm the crit?

That's not necessary. Especially with the variance of a Defense roll being considered. Leave the critical threat range alone. If you are going to modify it, just stick with increasing the threat range by +1 per 5 pts your attack roll exceeds the target's defense roll. You're going to have plenty of opportunity for crits without overbalancing.

Also, in any version of D20, characters rarely ever face something of truly equal/similar skill. One of the biggest problems is something is either too tough or too weak for the characters as they are. I believe True20 (as well as M&M) has rules for minions that make them easier to overcome without entirely eliminating the possible threat they represent. I would suggest using those (one being the inability to critical a hero--which you could keep or ignore as needed).