Why THAC0 Rocks

[Thondor]

First, memorizing all of those things wasn't necessarily that hard. I managed to do it, and I'm not that bright! Second, the many different subsystems also had at least one advantage over the unified mechanic: it meant they weren't as interwoven mechanically, and a bonus here didn't always affect a score there. In the long run that's a lot less calculating and fiddly bits to worry about during character creation as well as play. They were also more modular, thus, you could houserule/remove, for example, the saving throw system, without it affecting the entire fabric of the game.

Just some thoughts, and I think it reinforces the OPs idea of questioning things that are "obviously" true. There are always going to be people who have another view, and if you listen you might not change your mind, but you will probably learn something.

Very well said. There are almost always some advantages to doing things a different way. How the collection of advantages and disavantages compare between options is how you should decide. I think most people don't know or haven't fully considered some of the advantages of THAC0 compared to BAB. It certainly isn't naturally inferior.

As an aside the modularity of pre 3.0 A/D&D is one of its great strengths. I personally love the iniative/surprise rule that use a single roll of a d6 to determine if the group is surprised and which group goes first in one roll of a d6.
Some people don't they replace it with some other mechanism. No worries, it really doesn't effect much else.