Homebrew Critical Hit Model

[Brewhunter]

Ok I play Pathfinder with a group of friends online and I find the confirmation of critical hit tedious and unfair to players. So I would like to ask some experienced gamers to review the following model. Take the AC (or modified AC) of the creature +5 + Creature HD.
For an example: Basic Goblin
AC 15 + HD 1 + 5 = 21 or better for a critical hit.

So if a character rolls anything with modifiers between 15 and 20 they do normal dmg. But if they get 21 or better they get a critical hit. I use the critical hit decks so not every critical hit is double damage.

Now the GM can manipulate these numbers by increasing HD, using terrain, surprise, ect.

Thoughts and criticism are greatly appreciated.

[Da'ath]

I'm not trying to pee in your cheerios, but I'd go a simpler way, primarily because anything that adds additional math to the table slows things down and as a GM, I am lazy when it comes to this sort of thing (we make enough rolls, do enough math, and so on as it is).

Natural 20? Auto-crit (especially since a natural 1 is an auto fail).
Any other crit? Confirm it.

Doesn't really step on a fighter's toes, as he gets to auto confirm all threats at 20 with his mastered weapon, so no problems there.

Of course, this assumes you're using the standard crit rules. I use the +10/-10 crit/fail rules instead.

[Brewhunter]

Da'ath wrote:

I'm not trying to pee in your cheerios, but I'd go a simpler way, primarily because anything that adds additional math to the table slows things down and as a GM, I am lazy when it comes to this sort of thing (we make enough rolls, do enough math, and so on as it is).

Natural 20? Auto-crit (especially since a natural 1 is an auto fail).
Any other crit? Confirm it.

Doesn't really step on a fighter's toes, as he gets to auto confirm all threats at 20 with his mastered weapon, so no problems there.

Of course, this assumes you're using the standard crit rules. I use the +10/-10 crit/fail rules instead.

I played AD&D back long time ago and found the natural 20 to be a bit of a pain when as a DM you have a challenging final boss lined up for your characters and he gets cut down in 5 rounds. I'm thinking with this model I can temper power players with a simple AC, HD adjustment. The math is simple enough and if it is too much for the GM then the GM can inform the players of their natural damage and critical damage range. Or the calculations can be made ahead of time as the math is based solely on the monster not the player. I got a game for Wednesday night and will see how well this works out. Playing online I am able to make calculations in Excel to handle any of the crazy math. Thanks for the input though. New bowl of cheerios poured. :P