## Monday, April 14, 2008

### Moron Rolling To Hit

Warning: Superfluities Ahead!

Again with the RTH thing? Yep, then I’ll close that Can o’ Worms for now.

As covered in my last post, the Solstice RTH formula is:

20 minus (RTH + FC) = the AC ‘hit’ with that roll.

As used in Solstice, the above formula assumes a fluid AC and a fluid FC (Fighting Capability). I wasn’t specific about the FC in the previous post, but FC in the above formula is fluid in that it includes the attacker’s FC, plus any bonuses appropriate for that attack (from magic, abilities, positioning, etc).

Once one is able to accept FC as a replacement for Attack Matrices used in older versions of D&D, and is willing to use fluid AC, the simplicity of the above formula is clear. Fluid AC should be easy to grasp, as really the only edition to not use fluid AC was OD&D (the LBB).

Why all the hubbub about the OD&D combat system, rolls to hit, and AC? Well, knowing now what I know about d20 combat and how it actually works, I simply cannot resist improving upon the original model as presented in OD&D. Is it considered an improvement by everyone? No, clearly not. Many players prefer to use those LBB as is. There is absolutely nothing wrong with this mindset.

This brings me to the realization that the above formula, the Solstice method of determining hits and misses (which aside from adjusting the FC values, IS OD&D, just calculated differently) is only two steps away from the Attack/Defense model used in 3e and later editions.

As far as I’m concerned, this all started with the design decision to make numerically lower AC values better than numerically higher values. I should really invest in a PDF of CHAINMAIL to gain better insight into this issue, but nevertheless I will stick with my opinion that if the original rules had used the mindset that higher is better for AC, such derived formulae for determining hits and misses wouldn’t rankle old school players as much as they seem to do.

From what I understand, Dave Arneson at one time used an inverted combat system which essentially was the later edition version ‘turned upside down’ so to speak…in other words rolls to hit actually WERE attempting to ‘match’ the target’s AC, but lower rolls on the d20 were better. So, a roll of 4 would hit AC 4, and a roll of 20 was the lowest possible result. Perhaps somewhere in the translation of the Blackmoor campaign into the OD&D rules, only half of this system was properly converted. On the other hand, maybe this is explained better in CHAINMAIL. Nevertheless, it is clear that the method of matching the target’s AC with the roll on the d20 is nothing new.

There’s no need for an Attack Matrix with such a system, and it’s NOT a new idea at all.

Thus I arrive at the notion that the backwards AC system is really at the root of so much teeth gnashing. As such, in order to further simplify the D&D roll to hit method, I need to do one of two things:

Either invert d20 rolls into ‘lower is better’ ala Arneson, OR

Invert AC into ‘higher is better’.

Doing one or the other will distill the above formula into something *cough* resembling newer editions of D&D. In order to invert d20 rolls into ‘lower is better’, I’ll need to make any and all bonuses ‘to hit’ act as a negative instead of a positive. This is how the upside down, current AC system handles Protection, +1, or Armor, +1, it’s actually all -1. That’s accepted.

It seems much more logical to invert AC, and just use protection or cursed modifiers as listed, +X is good, and -X is bad. Now we’re getting somewhere.

Inverting AC is easy with the 20 number combat model, just subtract the fluid AC from 20 to achieve the actual AC of the target. Base AC becomes inverted so that AC 3 = AC 17, and AC 9 = AC 11, for example. This allows for a much more intuitive target value that needs to be matched or exceeded in order to score a hit. And we remove the ‘20 minus’ step of the Solstice formula. The new formula becomes:

If (RTH + FC) is equal to or greater than AC, a hit is scored.

Yep, it’s the later edition method using Attack and Defense values. Converting it is simply subtracting existing AC’s from 20.

It’s lean, mean and clean. And, it’ the natural, logical progression of things. Maybe I’m the moron, since I can’t understand why this distilled system is frowned upon by old school players.

Solstice will still stick with the counterintuitive upside down AC system, leaving the ‘20 minus’ step in the formula. I’ve taken away the tables, but I don’t want to take away the accepted AC system…not yet, anyway.

Hopefully I can retain my ‘Grognard Membership Card’. Solstice is still OD&D, and I can prove this by backing out all of the formulae into the raw components of the OD&D system. Admittedly, I did change the Attack Matrix values, but not the d20 combat model used to calculate hits and misses.

OK, I’m putting the lid back on this can for now.

~Sham, Delinquent DM

Subscribe to:
Post Comments (Atom)

## No comments:

Post a Comment