Dice and order of operations

Hi there. I was wondering if it is possible to use parentheses for order of operations purposes when doing math formulas with the dice? My group uses Thac0 in our game, and our attack roll formula to determine armor class hit is Thac0-(1d20+modifiers) doing so without the brackets adds the modifier result to the end, which gives the opposite desired result. Right now we are working around it by using Thac0-1d20-modifiers, but ideally I'd like to find the right formula to have the modifier added rather than subtracted so the newer players become less confused. Any thoughts? using brackets in the die roller produces an error. Is there another way to specify which numbers are used first?

Wow, THAC0. I just wanted to say that. - Gauss

Yeah, a lot of things I liked better about 2nd edition. But Thac0 is not one of them :)

Of all the changes from 2nd to 3rd edition the main one that I love is that numbers finally made sense. The rest could stay or go but if I were to update 2nd edition I would convert it to 3rd edition style to hit rolls and AC. - Gauss

Wouldn't be too hard really would it? Just reverse the direction AC increments and instead of thac0 tables add a BAB at the rate of which thac0 decreases for each class. Though I still sort of have my heart on keeping this part as true to the books as possible, at least until our new players figure out how it works. I want them to be able to reference the rules and figure things out on their own as much as possible without having to ask questions and deal with a load of exceptions until they get the hang of how a pen and paper game works.

THAC0 is actually pretty easy. Chad Perrin explains it pretty well here: <a href="http://sob.apotheon.org/?p=1088" rel="nofollow">http://sob.apotheon.org/?p=1088</a> Basically, add the opponents AC to your roll. If the result is higher than your THAC0, then you hit. So for an Orc with an AC of 4, roll 1d20+4. If that roll is greater than your THAC0, you hit. Else, you don't. Same applies for negative ACs. You just add a negative number, so you subtract it. So a creature with -2 AC works like this: 1d20-2. If it's greater than your THAC0, you hit. The only real problem with THAC0 is that it means either the GM does extra work, or the players have to know the opponents' ACs.

THAC0 was always cumbersome. I played and GM'd 2nd edition for 10years but was overjoyed at the new system that made calculating numbers easier. And I am not math challenged. For the math challenged THAC0 was impossible. 3rd edition opened up the game to the math challenged. - Gauss

THAC0 is easy enough to do in a macro; this is how I do it for my D&D Rules Cyclopedia, game: THAC0-1d20 = Armor Class hit Example: Thorin Ironshanks (2nd level Dwarf, STR-16) has a THAC0 of 16 with his +1 warhammer , and his warhammer macro looks like this: /r 16-d20 \ hits Armor Class... /r 1d6+3 \ +1 warhammer damage

Hi Drohem, that is currently how we do our rolling. However the problem lies in when the player has modifiers to hit, such as a strength bonus or from weapon specialization. In theory we should be able to go THAC0-1d20+Modifiers but what it does is it adds the modifiers after subtracting the d20 from THAC0 rather than adding to the roll and then subtracting the total result. This ends up with the reverse of the desired effect. So I am wondering if it is possible to specify which order the math is performed in, such as with the use of brackets.

Yeah, I hear you as I ran into the same problem myself when setting up macros for my game. :) You can still use the '+' function with the macros, but only in a very narrow and limited sense currently: It works if you reverse the modifier to the macro, and the macro is a very simple one. For example, this works fine as a macro with modifier... /r 16-d20+ For the example, let's say the character has a +2 bonus to the attack roll. Therefore, you would type in the macro and '-2' as the modifier. However, this function ceases to work properly if you add anything to the macro after the '+' function. As seen in my example in the previous post, I like to add a small descriptor to the macro using the reverse backslash ('\') after the dice command. However, if you do this then the '+' function at the end of the dice command will fail to operate, and thus the macro will fail to execute. Currently, I just mentally add/subtract any modifiers to a macro and type the adjusted roll result directly into the Chat. This is my workaround to the limited Modifier function of the Dice Roller because I like to have those little extra descriptors in my macros. Now, if you don't mind using very basic macro functionality in order to incorporate the Modifier function of the Dice Roller, then it can be done.

You can make a basic macro like: /r16-d20 Name it 'Attack' and then type #Attack +2 in the chat window and it works right. You don't need the + after the d20 for it to work.

Sure, but when using THAC0 you have to reverse the modifier to the roll (i.e., a positive modifier becomes a negative modifier, and vice-versa). Also, this only works if there is nothing else in the macro after the '+' notation.

So put whatever you were going to put after the roll before it.