Monday, March 11, 2019

To Hit Mechanics

Here's your random shane thoughts for the day!  I'm running on a bit less sleep due to the time change and not going to be earlier enough.

I've got some thoughts on To Hit Mechanics in old school D&D type games.  Having recently played TBH, which has an interesting way to do "to hit mechanics", I've started thinking about mechanics overall and how they are all very similar (despite people yelling and screaming that one is better than the other).

Ascending AC to hit  is basically roll a d20 and add whatever STR/DEX mod to it (and/or attack bonus).  Example, to hit an unarmored orc I need to roll a 10, I roll a 6 + 3 and get 9.  Which I count on my fingers everytime!

Descending ac, the orc has an AC of 9.  I check my THACO (at first level), and find out that in order to hit the Orc I need 10.  (thaco - armour class).  Which for some friggin reason is way easier in my head.

for the black hack, it's roll under your appropriate stat.  If you are using a sword it's roll under strength, if you are using a bow and arrow its roll under dex.  However if the monster  has more than one hit dice, you have to add that to the roll.  So as an example If I'm trying to hit a 4HD orge and I have a dex of 15, I need to roll under the 15 but with +4.   Let's say I roll a 10 and then with the +4 I am at 14, which is under my dex.  Once again I'm counting on my fingers.

Honestly I think it really depends on how someones brain works.  For me descending somehow makes the most sense, because I have a target and I have to hit that.  Here's the number, roll the dice and if I'm over excellent!

VS both of the above I roll and then add to see if I have accomplished the task.  So somehow it's an extra step kinda....


  1. Monster THAC0 is the easiest. HD + AC + roll = 20+ is a hit.

    Lately I’ve used an attack matrix. Just have it on the front and back of the ref screen and people can cross reference

    1. You are totally correct, and I just now realized how is that is. Too bad it doesn't work in reverse for players. 20-player level - ac.

  2. I've been drawn towards the Whitehack version, which is basically rolling above the monster AC and below the relevant attribute. Crits when you roll the attribute value. I'm toying with using such a mechanic to remove dice roll modifiers entirely from all task resolution:

    Difficulty ≤ d20 roll ≥ Attribute

    The GM sets the Difficulty of a task, which if attacking is the AC, if defending is the monster's attack bonus. Anything else can be assessed by the GM.

    I like that it means that means that everyone will know a success or failure as soon as the die stops rolling. They are told the difficulty, know their attribute and roll, knowing they need a number between x and y. No need for the "I get...[pauses to scan their character sheet for the modifier]...a 14!"

    If the system does have attack modifiers for the players and the like, it can be taken from the difficulty before the roll.

    A bit of a change of mindset from the 'Nat 20' type of gameplay, but probably just as much as the one required to shift to a roll under system.

    1. That sounds very similar to the black hack.

    2. Going by the names I'm sure one must have been influenced by the other (I'm guessing TBH from TWH but am fully open to being corrected!). I like how the roll between but roll high mechanic fits a little better with TBH's usage dice - it avoids the 'nat 1 is always a critical success unless it isn't' rule. Rolling high is still important.

  3. I don’t have any problem with people saying ascending AC is easy. I only have trouble with people saying descending AC *isn’t* easy. Simple subtraction! :)