AC: A simplified suggestion

[Cyr]

The AC system falls apart fairly quickly in game. Basically lower AC's are pointless and while leveling very high AC's are equally pointless.

So the goals here are simple to any rework...

• Lower AC's should make a difference against all mobs at all levels of play.
• Very High AC's should make a difference against all mobs at almost all levels of play (the extreme twinkage possible at the lowest levels of play is going to be deemed not important enough to worry about).
• Create a system where grazing hits are no longer needed to insure some incoming damage in raid type fights.
• Insure that AC still does not protect against 'spike' damage...ie no static type dr stuff for AC since spike damage helps retain the danger element in game.
• Create a system where there is less concern over that last point of AC being achieved which likewise frees the developers to be less wary when making new AC gear or other buffs.
• Insure that any future increases to mob to hits or player ACs will not break this system. IE make the AC system work well within the framework of an expanding game.
• Eliminate the needs for any 'special' AC related rules as band aid fixes on a broken system.

So what do I propose?

• Eliminate grazing hits.
• Eliminate epic special rules involving to hit roles.
• Change how ALL mobs roll to hit as follows...
  
  • Mobs now have extra d20's to hit instead of base + to hit. This change would be made so that mobs have the same average to hit roll. Extra d20's would be assigned until the mob has less then a static +11 to hit.
  • Critical hits would be assigned a percentile chance of occurring based upon the mobs previous crit range and would be assigned in the proper upper range of rolls possible. This is simple for a computer to do.
  • Automatic hits and misses would be assigned as a ~5% chance based upon the d20 rolls being done to preserve that these are the top 5% of rolls or bottom 5% of rolls possible from the range being rolled. This is very simple for a computer to do. Note, I would not be opposed to elimanting these automatic misses and hits entirely as the dynamic ranges are much much larger in my proposed system then the current system making these less critical.

In practice what would this mean?

• Mobs could roll worse (much worse) then normal meaning that even the most minor investments in AC would add some protection against incoming attacks. A mob with a truly massive to hit roll currently that had let's say a 1d20 + 90 would instead have a to hit roll of 9d20 + 6 meaning anything over a 15 AC would provide some added protection versus their attacks. Even a raging barbarian can manage over a 15 AC if they bothered to do so.
• Grazing hits are not needed because mobs can roll crazy high to hit players. That same mob above could roll to hit a 186 AC. Also this lifts some of the headache from the developers when designing new items with AC in mind as there is no longer a 'magic number' that must be avoided otherwise content becomes trivial.
• Massive AC numbers do provide extra protection, but at a degraded rate as mobs are less and less likely to roll each AC to hit the higher they go over their average (unlike the previous 1d20 system where the odds of them rolling that number is exactly the same as rolling the average).
• Lower AC numbers before a mobs average to hit provide more and more protection as you approach their average to hit.
• Developers can create mobs with smaller then prior average to hits without strong worries about creating 'invincible' players. Likewise their old favorites of super high to hit mobs fit better in the overall structure of the game. This provides lots of wiggle room for content designers as they are not constantly having to worry about falling off the dice.

If anyone wants practical examples of any math I should be able to provide it.