So first I suppose I should start out by outlining my system's conflict resolution mechanics.

Everything (or as near to it as I can) that a character decides or attempts to do stems from their Core "characteristics"
(referred to in the rules as the Core 11)
The Core 11 consists of
Might - Prowess - Precision - Agility - Forbearance - Heartiness - Perception - Knowledge - Reasoning - Communication - Appeal
There is a brief breakdown of what they are HERE

All characteristics act like ready bonuses to add to a roll (usually a d20)
why a d20? Because I like its odds for criticals 1 in 20 for both types. 
Characteristics can range from 1 to 10 making my game a game of LARGE bonuses.
which is another reason the d20 works well. (it evens out these large(r) numbers with number equal to them)
The problem with criticals in my game is that there is both a defensive and offensive roll (in all conflicts) and the chance of both "attacker" and "Defender" rolling one... see later example

These characteristics work together to create sub-stats such as:

• Melee or Ranged attack bonuses
• Preservations (or saving throws)
• dodge and parry bonuses
• Social Conflict resources such as - Resolve - Argument - Composure
• and skill category scores


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I'll use a combat scenario (very familiar to most gamers) to provide my Critical strikes/fails issue.
[sub]I will leave out roleplaying to better illustrate the mechanics[/sub]

After initiative is determined (Agility+1d20 .. Highest first)
The players decide there characters actions
The attacker chooses how to attack and makes an attempt
attacker Rolls a d20 and adds the respective bonus (we will assume "Melee" for this example)
Defender Decides what type of Defense to take (we will assume Parry - due to its +3 shield bonus)
Defender Rolls a d20 and adds the bonus.
The Dice Rolls are compared, The Attacker's attack Rolls a Natural 20 as does the Defender
Critical Attack and Critical Defense [sub](though I use the term "exceptional" rather than "critical" in my game - makes more sense to me)[/sub]
The players consult their player sheets and compare Stats.
attacker has the bonus of 17 to melee
Defender has the bonus of 14 to parry + 3 (medium Round shield)

How would this scenario fairly play out?
This has happened during playtesting and as a fix I did away with "criticals" but players started whining
and I think they are right. In other games Criticals were always a great source of excitement during play.
Furthermore It IS one of the reasons I worked the d20 in as the major force in conflict resolution.

The idea of following suit that the attacker always triumphs as a result of a tie (which is the case of a normal attack)
seems to cheat the defender in such a way that when it ever happens it always leaves a bitter taste in the mouth of that defender.
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Just a little auxiliary information that may help

I tried to model all conflict resolution after the same mechanic.
Opposing rolls - one defensive - one offensive
this is true for magic as well as social conflict
(though social is a little different since I force players to roleplay "attacks" -- see thread HERE)

It goes like this

Melee/Ranged attacks --- Vs. --- Parry/dodge
Argument (attacks) --- Vs. --- Composure (defense)
Spell power --- Vs --- Preservations (or saving throws)

skills are a little different and outlined HERE but criticals aren't an issue
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What I need:
Any help you guys can offer on how to resolved this issue.
How do other games deal with this issue?
Do you think it would be unfair to have the attacker or defender win "draws" by default?
is there any way to determine a the "winner" of a draw (tied scores/rolls)?

thanks a ton guys.
-Brent

Simplest to my mind would be to have critical (exceptional) offense and defense cancel each other out.

What I don't like about this system that your chance of rolling a critical is the same, no matter what your chance of hitting the other guy are. Maybe all you need to roll is a 6+ to hit - you still only get a 5% of a critical; if you do hit, your chance of a critical is 1/15 or less than 7%. Or you will only hit on a 20 - but that hit would still be a critical, so if you do hit, your chance of a critical is 100%.

I think it was RuneQuest (???) that used a d100 system, you had to roll under a number to hit, and every multiple of 5 was a critical hit. So if you had to roll 70 or less, you would hit on 5, 10, 15... so on to 70; or an overall 12% chance of a critical. If you had to roll a 20 or less to hit, you would get a critical on 5,10,15 and 20, or overall a 4% chance of a critical. I always liked that mechanic because it increased your chances of a critical with your to-hit chances.

The first section here is just non-issue game information skip ahead to the page break line for relevant text
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I didn't mention some aspects of my systems combat system mostly because I didn't think that they were relevant to the issue at hand but just to hopefully allow you to like my system a little more...

Each of the 20 character classes have class specific "actions"
The player gets so many depending on level to choose from
Some are combat related - others are magic related - others are social skills and such.
Players get to decide which to take. Some of them give bonuses to critical strike chances.

Example from my "Reaver" Class
Reavers are people who feel that you should be strong enough to protect your belongings.
Those who are stronger have the right to take from the weak. This of course applies to them as well.
examples of actions available to the reaver class

Notice Weakness - Takes one round to look for an opponents weakness.
Effect- Exceptional attacks are made on a natural roll of 17 or higher when attacking
This effect will last until the opponent is defeated/victorious or changes tactics/retreats.

Seem Inept- if a mental Preservation (save) is failed an attacker will receive a negative equal to half the PC's level to their attack-die
While seeming inept attackers must roll a mental Preservation before each attack.
While seeming inept PC's are allowed only 1 attack per round no matter armor, special abilities or items.

Please note that these notes aren't finished "actions" but what are currently used during playtesting. My core rules will (hopefully) be more elegantly written and grammar will of course be cleaned up.

Hope that helps see the bigger picture.
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On a thankful note.
I will have to consider some alternate forms of exceptional strikes/fails.
1's and 20's are easy to remember but perhaps another way can be thought of.
Its not at all uncommon for someone in my game to roll a 27 or even 34 (d20+bonus)
So maybe theres a way to use these High numbers
Say 10pts over an opponent's parry/dodge roll is a critical? something like that
Green Ronin's Song of Ice and Fire RPG has something like that but its not used for criticals.
You tally how many Points over your opponent's defense you go and reference a chart (well we used to reference it - its easy every 4 pts)
to see what "degree" of success you had. for each degree your damage increases.

Having them cancel one another out is the same as the defender winning. The Attacker then feels like although he rolled a 20 - he somehow lost and his excitement at seeing that number was for nothing. the feeling isn't great, and it detracts from the fun of the game.
I don't know. Its a hard issue. Which sucks cause I currently feel like my game is broken. :(
But I really Thank You for the input.

-Brent

What does a critical success for a defense actually represent? 

Hi Brent,

Necromantis wrote: Having them cancel one another out is the same as the defender winning. The Attacker then feels like although he rolled a 20 - he somehow lost and his excitement at seeing that number was for nothing. the feeling isn't great, and it detracts from the fun of the game.

Hey Brent,

In my experience, the single RPG system which has managed to make opposed d20 rolling and critical results really work is used in HeroQuest. I think it'd be useful to see how that works, whether to say "oh, that's how," or "no, but I see how I'm going to do it differently."

Here's a link to the PDF Rules summary, which is organized by character creation, reward system, and resolution (starts on page 6). I think it's the right system for you to be checking out.

Best, Ron

Ar wrote:
What does a critical success for a defense actually represent? 

Chris_Chinn wrote:
1) A tie breaker roll between attacker & defender.  Things could go either way!  Exciting, and granted, one side or the other "gets nothing" for the roll, but at least they had a chance.

Ron wrote:
Hey Brent,

In my experience,...
...it's the right system for you to be checking out.

Best, Ron

Ron wrote:
Hey Brent,

In my experience, the single RPG system which has managed to make opposed d20 rolling and critical results really work is used in HeroQuest. I think it'd be useful to see how that works, whether to say "oh, that's how," or "no, but I see how I'm going to do it differently."

Here's a link to the PDF Rules summary, which is organized by character creation, reward system, and resolution (starts on page 6). I think it's the right system for you to be checking out.

Best, Ron