This thread is turning into an edition war, and a lot of bickering and insulting. Perhaps it's time to move one with our business, or take the insulting to more personal forms of chat.
1. Roll a die 2. Add your bonuses 3. Report results to the DM 4. The DM tells you if you hit 5. You do the incredibly simple math in your head to figure out the creatures AC in any system
You're missing a step between 2 and 3, unless you assume that the DM knows the THAC0 of all players. I'm not saying it's hard to figure out THAC0, but I AM saying that it's a more complex system than BaB.
If you're really reluctant to agree that THAC0 is a more confusing system than BaB, then you're just being stubborn.
Again, I'm not flaming on 2nd edition. I've enjoyed the system for years. But it has it's downsides, especially towards the needless complexity with some of it's rules, as well as oddities with some of it's other rules.
I don't think THAC0 is worse than BAB, mostly because while BAB is simpler it exists specifically to support what I consider an awful multi class system. Figuring out your THAC0 is simple. It's a linear chart. Figuring out your BAB is based on calculations of how many levels of what class. Your DM knowing your THAC0 isn't a huge expectation but your DM knowing everyone's BAB is a much less likely arrangement after a certain point
I think that race/class restrictions are entirely by setting.
If Mystra, goddess of magic, says Dwarves can't use magic then so be it. If every single paladin order in the whole world says no halflings, so be it.
For my own personal setting where I DM? No race/class restrictions.
Edit: Basically settings should have race/class restrictions, generic rules should not.
Edit the second: In the 5e DM's guide there's actually suggestions on how to handle race/class restrictions if you want to use them and gives examples like maybe different races use different arcane magic. All elves are bards (with wood elves being valor bards and all high elves being lore bards) or all dragonborn having sorcerers, all human arcane users are wizards, etc. Just suggestions on how to flavor the world using race/class restrictions.
@PK2748 People who think themselves smart or good at math because they "get" THAC0 have no clue. No, THAC0 is not difficult. Yes, most people think working with non negative numbers is more intuitive. Hence, BAB is more intuitive.
BAB isn't just more intuitive because it uses consistent positive numbers (though that certainly helps), but because the properties of the character and target are more consistent.
Under THAC0 you roll a dice, modify what you rolled by a property of the target (their AC) and compare it to a property of your character (your THAC0) to see whether you hit or not.
Under BAB you roll a dice, modify it by properties of your character (your BAB) and compare it to a property of the target (their AC) to see if you hit or not.
With BAB properties of your character more consistently apply to your character and properties of the target more consistently apply to the target.
Anyway, race restrictions were a thing in 2E because 2E D&D has opinions about what kind of fantasy you are engaging in, if you're using elves and dwarves you're using them roughly the way the designers imagined them.
@PK2748 People who think themselves smart or good at math because they "get" THAC0 have no clue. No, THAC0 is not difficult. Yes, most people think working with non negative numbers is more intuitive. Hence, BAB is more intuitive.
Actually how is working with positive integers more or less intuitive? Subtraction and addition are equally "intuitive" and a negative number in this context is just subtraction. Intuitive and simple are not synonymous.
"Notoriously difficult for pupils to understand, I think addition and subtraction of negatives is one of the things that one comes to understand after doing lots of practice."
@PK2748 People who think themselves smart or good at math because they "get" THAC0 have no clue. No, THAC0 is not difficult. Yes, most people think working with non negative numbers is more intuitive. Hence, BAB is more intuitive.
Actually how is working with positive integers more or less intuitive? Subtraction and addition are equally "intuitive" and a negative number in this context is just subtraction. Intuitive and simple are not synonymous.
The intuitive thing about the numbers isn't necessarily working with positive numbers, but that in newer editions bigger numbers are consistently better, whereas sometimes in older edtions smaller numbers were better and sometimes bigger numbers were better and sometimes negative numbers were better. You want a big strength which makes your THAC0 better, but a big THAC0 is bad because the big strength made it smaller.
Comments
If you're really reluctant to agree that THAC0 is a more confusing system than BaB, then you're just being stubborn.
Again, I'm not flaming on 2nd edition. I've enjoyed the system for years. But it has it's downsides, especially towards the needless complexity with some of it's rules, as well as oddities with some of it's other rules.
If Mystra, goddess of magic, says Dwarves can't use magic then so be it. If every single paladin order in the whole world says no halflings, so be it.
For my own personal setting where I DM? No race/class restrictions.
Edit: Basically settings should have race/class restrictions, generic rules should not.
Edit the second: In the 5e DM's guide there's actually suggestions on how to handle race/class restrictions if you want to use them and gives examples like maybe different races use different arcane magic. All elves are bards (with wood elves being valor bards and all high elves being lore bards) or all dragonborn having sorcerers, all human arcane users are wizards, etc. Just suggestions on how to flavor the world using race/class restrictions.
Under THAC0 you roll a dice, modify what you rolled by a property of the target (their AC) and compare it to a property of your character (your THAC0) to see whether you hit or not.
Under BAB you roll a dice, modify it by properties of your character (your BAB) and compare it to a property of the target (their AC) to see if you hit or not.
With BAB properties of your character more consistently apply to your character and properties of the target more consistently apply to the target.
Anyway, race restrictions were a thing in 2E because 2E D&D has opinions about what kind of fantasy you are engaging in, if you're using elves and dwarves you're using them roughly the way the designers imagined them.
"Notoriously difficult for pupils to understand, I think addition and subtraction of negatives is one of the things that one comes to understand after doing lots of practice."
http://mrreddy.com/blog/2014/07/how-we-teach-addition-subtraction-of-negative-numbers/
"The most difficult aspect is to subtract a negative number."
http://www.education.vic.gov.au/school/teachers/teachingresources/discipline/maths/continuum/Pages/negnum45.aspx
People need cheat sheets to do these operations
http://math.about.com/od/prealgebra/ht/PostiveNeg.htm
People need 'how to's to do these operations
http://www.wikihow.com/Add-and-Subtract-Negatives