Thursday, March 29, 2012

Some Thoughts On Criticals - Curving the Scores

Some people love criticals in their games.  Some hate them.  I tend to be on the fence.

Lets face it, they add excitement for the players, but they are also a hidden albatross, wearing down the players' hit points more over the long term than the cannon fodder they are dispatching.

Additionally, they tend to be a fixed number.  Natural 20 is a common on (you crit 5% of the time, whether your chance to hit is 50% or 5%), or its a range of numbers, usually depending on weapon (thinking 3x here), something like 18-20.

What is the usual critical effect?  Maximum damage or double damage.  Why, because it's simple to figure out.

Here's my thoughts (not that I'm finished thinking) on the matter.

Why don't we make it range dependent upon the number you need to hit.  Something like "all rolls 5 or better than the score you need to hit may be a critical.  Please refer to the critical table".  This means the better your chance to hit your opponent, the better your chance to possibly critically hit him.  Additionally, if you barely have a chance to hit him, you have no chance to score a critical.

Critical Table  (Roll 1D10)
1-3   Normal Damage only
          4-5  +2 To Hit on your next attack against your opponent (You are pressing your opponent)
6-7  +2 To You AC until the end of your opponent's next round (You have your opponent off balance) 
8-9  Get the benefits of the above two rolls (+2 Hit and +2 AC against your opponent)
10  You have an opening! Get a free attack immediately against your opponent!  Your free attack may also be a possible critical if you roll high enough.

This does away with automatically adding damage to the attack, while still offering bonuses for the player (or the monster).


  1. Yeah, my crits table is all "drop a weapon, fall down, get knocked back, get stunned" kind of stuff. There is one double damage effect but it only happens 1/18 times.

    One caution though: crit on 20 is a lot easier to remember in action than the 5 point rule.

    I'd rather reduce the crit chance than have a no effect result on the table. Kind of an anticlimax.

  2. I've never liked the 'natural 20' critical in D&D for the same reason that you are uneasy - the clumsiest Goblin will roll a critical hit as often as will Conan.

    I think you're right to make criticals in some way dependent on fighting ability - in RuneQuest and related games it is usually some percentile (usually 5, 10, or 20%) of the skill that the character is trying to roll under. In simple games such as OpenQuest, the result of a critical is simply maximised damage. In more complex versions, achieving a critical has quite colorful effects - either an effect based on the type of weapon (slashing, peircing, crushing, say), or, in Mongoose RuneQuest II/Legend, the choice of a whole range of interesting 'combat manoeuvres'.

  3. I think this somewhat depends on what you are defining a critical hit to represent.

    If a critical hit is a skillful exploitation of an enemy opening, then five above what is required to hit seems right.

    But if a critical hit is trying to represent a "lucky" hit - the bad guy accidentally impaling himself on the trembling farmer's dagger - then an arbitrary number is a better mechanic.

    In my opinion, of course.

  4. Long ago, in the before times (AD&D 2e era, somewhere in the mid-90s) I had a similar idea but easier to apply implementation.

    Roll to hit normally, but look at the actual die value. The results were something like

    20: automatically hit. If it would have been a miss except for this rule, you do half damage.
    16-19: normal hit or miss.
    11-15: hit or miss, double damage on hit
    6-10: hit or miss, triple damage on hit
    2-5: hit or miss, quadruple damage on hit
    1: (probably) automatically miss. If this would have been a hit except for this rule [some benefit I forget]

    I don't remember exactly what '1' was because I don't think it ever came up.

    Mathematically this is very similar to what you're describing.

  5. Combining the two tables (without trying too hard to match frequencies) you could have:

    20: automatically hit; half damage if you would have missed without this rule.
    16-19: normal hit
    12-15: +2 to hit on next attack against this opponent [or any opponent?]
    8-11: +2 to AC until the end of your next turn [full round effect, against all comers]
    4-7: both the above effects
    1-3: free attack -- against same or other adjacent opponent

    I turned the effects up a little, and narrowed the ranges slightly from my previous table. In this model a critical doesn't necessarily mean that you hit the current target better (which is what bonus damage indicates) but that you are able to put yourself in a really good position.

    I also dropped the fumble entry (automatic miss). In AD&D and D&D 3.x the higher your BAB the more attacks you have, and thus the more opportunities to fumble... which seems lame. Automatic hit on a 20 is throwing a bone to the utterly outclassed (and because I halve damage in that case it's a small bone), but if you can hit on a 1 you so outclass your opponent you deserve it. Let it happen.


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