There should have been a sidebar with THAC0 description in DMG 5E. I was looking forward to it as I heard good recommendations on it, but never really played it because I started game with the 4th edition. I've read DMG cover to cover but didn't find any such sidebar. Have I missed something? Is it somewhere in the 5E rules?
CCS wrote:
THAC0 is something i could see featuring in one of their upcoming Unearthed Arcana column.
If you know the AC:
AC 2
Thac0: 12
12 - 2 = 10+ to hit AC 2 with a d20 (plus modifiers)
Subtract the target's armor class from your thaco and that's what you need to roll (or higher) to hit on a d20 + modifiers.
Or if I don't know the AC of the target (which is usually how it works on the player's side):
Thac0: 12
D20 + modifiers roll: 8
8 + 4 is 12
I tell the DM I hit armor class 4
If I rolled 14 instead:
14 - 2 = 12
I tell the DM I hit armor class -2
Thac0 really isn't as hard as people make it out to be.
You only ever had to look at the thac0 table for your class once whenever you level up, simply as a part of the levelling up process like checking how your saving throws change. It's not like you had to consult the table every time you had to roll.
I don't know who would recommend THACO to you, but they were probably being sarcastic or having some fun with you. As others have said, each class had their own table with an attack progression. Basically you wanted to roll high, like you do now. Your AC improved by going down in number, not up. THACO is "to hit armor class zero", so if you had a high THACO it was harder to hit enemies. Streamlining the whole combat process so that you had to roll high but AC and attack bonuses showed improvement by going up is a much easier system.
If I remember correctly (it's been a really long time since I played AD&D) Mellored, it was saving throws that you had to roll under the number. Somethings you had to roll high and others you had to roll low. When 3e came along, the entire system was changed so that you always wanted to roll high. It was so much easier to keep track of everything and teach new players.
No, it wasn't difficult. It was just more complex than it needed to be. It was basically the same system of dice rolls, bonuses, and target numbers, but with an unnecessary extra step of determining the target number to hit a given AC, instead of just calling the target number itself AC.
manduck wrote:
manduck wrote:
THACO of 15, that means to hit AC 0 (20 in 3rd/4th/5th Ed) you need to roll a 15, if the AC is 1, you only need a 14, and if the AC is -1, you need a 16.
Easy, but less intuitive.
The best part of Thac0 was simply that you could calculate each weapon one time, and have your different Thac0 numbers ready for each roll (of course, you can still do this, but it isn't quite the same without being actually more fiddly).
Since a + made it easier to hit and a - made it harder, you could do this:
level 7 fighter, base thac0 14 (Fighter Thac0 was 21-level) with an 18/00 strength (+3/+6 to-hit/damage) and specialized (+1/+2 to-hit/damage) with a sword +2/+3 vs dragons would be: 14-3-1-2 or Thac0 8 (Thac0 7 vs dragons). Now each level, his Thac0 would drop by one. So I'm fighting 3 creatures with Armor Classes of 7, 2, and -4. Respectively, with a Thac0 of 8, I'd need to roll a 2 (because a 1 is always a miss), a 6, and a 12 (8-7, 8-2, and 8-[-4]). It was literally 6th grade math.
Of course, under Common Core it might be year 3 collegiate math. 
Quasadu wrote:
Devils-Advocate wrote:
thehobb wrote:
CCS wrote:
Brock_Landers wrote:
THAC0 is Spinal Tap.
Just remember: 10 + X = 21 - X (hence where the eleven comes from)
... except for the small problem of constantly converting an easier better way, into something that takes more brain space.
Dougan_Axehammer wrote:
MechaPilot wrote:
The only difference between THAC0 and BAB is subtraction vs addition.
THAC0 involves using subtraction, BAB involves using addition.
For some reason (and this is true for me too, I just don't know the reason), most people find addition easier and more intuitive than subtraction. Thus, BAB is more popular than THAC0 despite them being fundamentally the same system.
Yeah. THAC0 isn't really that confusing. THAC0 - (die roll + modifiers) = AC hit. If there are no situational modifiers then it's just THAC0 - die roll because you probably already accounted for normal modifiers like Strength in your THAC0. In 5e there are always modifiers on the die roll and potentially modifiers on the AC side as well. You have to add particular proficiency bonus + ability bonus + possible weapon bonus to every single attack. So you are always doing math no matter which system you use.
Whenever I see people say THAC0 is hard I automatically assume they are bad at math.
ankiyavon wrote:
guachi wrote:
Devils-Advocate wrote:
ShadoWWW wrote:
awaken_D_M_golem wrote:
Devils-Advocate wrote:
For what it's worth, I never said it was any harder or worse than it is now, just more complicated. And yes, if you weren't as good as someone else at math, then THAC0 might be harder than it seems. Both THAC0 and AC had a negative progression (ie. as it got better the value got lower), and, at the time, was not the most intuitive. Algebra is not for everyone, and when using THAC0, everyone uses algebra, even you, thehobb.
Gatt wrote:
The_Jester wrote:
DungeonKrusher wrote:
THAC0 is in the 5e PHB, check the index.
although that is just another example of the designers sense of humour.
part
Gatt wrote:
I was just wondering what it was. A friend of mine told me he's been a big fan of AD&D. He read PHB 5e and told me it brought the spirit of AD&D back. He was very excited. He even said it looked even better than AD&D! He liked 3e and partly 4e, but AD&D has always been his number one choice. Now he addresses his formal players with request to play 5E, and he is very excited about it. His only minor discontent was his sigh "It's a pity that THAC0 is not back as well, and probably never will be..."
I also think it would be great if it was in DMG as an optional rule as was promissed. This discussion also shows it has many fans even nowadays.
ShadoWWW wrote:
Dark_Stryke wrote:
Cyber-Dave wrote:
MechaPilot wrote:
THAC0 worked in 2E simply because everything was designed around it, and there was no other option. Even all of the retro-clones avoid to-hit tables or THAC0-style, for good reason. To-hit tables/THAC0 were a product of their times, when tables were quite popular (this resulted in the ultra-chart-heavy game Rolemaster).
ankiyavon wrote:
THAC0 in 5th? Haha, nice prank.
Ganymede425 wrote: