thac0 (which some may think as offensive/defensive values) have been decreased in all three classes.
Blademasters were inherently more defensive, and more offensive than a warrior and vampire COMBINED. This has been changed to reflect a thac0 similar to warriors and vampires.
Bards have been reduced to their own thac0, just beneath thieves and ninjas as rogues, and a good bit above mages, like clerics and shamans.
THAC0 only affects AC pass/miss, not actual defenses, right?
So we are back to older values of bards?
And back to dual wield problems for not decked 60 hitroll bards.
Shouldn't be much of a problem, because dual wielding on a bard is worse than wielding an instrument in 2 hands.
Even if you offhand an instrument.
At least it will help most high AC opponents, like mages 
Thanks for the information.
What does thac0 actually do, after all?
I just want to chime in and say thanks for being both timely and responsive!
Bards thac0 is still lower than it was before initial changes (lower = better). You won't see a huge difference.
mya here is correct. thac0 determines how easy it is to hit someone through their armor class, and constitutes a small amount to your own thickness of armor class. A thief's -AC at 200 for instance won't be the same as a bard's at 200, nor will it be the same for a thief trying to hit a cleric or a bard hitting a cleric (thief will hit more and pass -ac more, as opposed to bard a little less).
So how hard did saders get gimped, the most customized class as a whole seems to get a blanket fox?
It's pretty insignificant as far as I can tell. If Morle didn't tell us we probably wouldn't have found out anyway.
So thanks for letting us know, Morle.
Atticus a crusader can get to -700 ac. I doubt this is gonna have far reaching effects on them.
Atticus a crusader can get to -700 ac. I doubt this is gonna have far reaching effects on them.
With all due respect, we have characters that are getting -800 to -900 ac without being a QClass. The possibilities have become drastically different in the past few months/years with the introduction of new equipment. That high level -ac is no longer exclusive. Its obvious as certain characters are already achieving this with relative ease. Why is this an issue? Because no matter your hit/dam you can't hit them.
I agree with the Crusader change, but more so just for High Sight. That particular path was obscenely strong. The others? I'm not so sure if a blanket nerf was the appropriate course of action.
Thanks trick, I couldn't have said it better.
Without going into specifics crusaders are still able to surpass other classes in ac due to selections and armor choice.
Does thac0 determine how well you defend* or how well you penetrate defenses, or it's just how well you penetrate the AC after you've penetrated the defense?
*Defend includes parry/dodge/dual parry/weapon block/shield block and(or) other similar.
thac0 determines how easy it is to hit someone through their armor class, and constitutes a small amount to your own thickness of armor class.
"it's just how well you penetrate the AC after you've penetrated the defense"
It just gets converted to zero damage when you fail.
The miss is zero damage verb. If a spell also does zero damage, it also "misses".
It's quite ingenious.
For what it's worth:
These aren't blanket changes. They were changed after numerous tests and me snooping pretty much every single time I was online (in conjunction with coding what I could in the new changes Volgathras and the other staff has come up with on Heralds). I didn't make these changes lightly. I made them with the intent to balance.
You can't actually believe that there wasn't anything wrong with crusader thac0, just as no one can tell me they didn't want bard changes (they didn't like how strong they were either). Blademaster changes to thac0 just happened to be something I glanced over, saw how incredibly low their thac0 was (if you'd like to know, it was -20, as opposed to -10 on warriors/vampires respectively) and changed it with the intention of slightly balancing them.
All but the players playing the classes listed will be happy, unfortunately, since it directly affects your character. If it doesn't affect you, however, and you fight and/or continually have problems with said classes, you're more than happy to agree with the change.
Can't make everyone happy. I just ask that you trust me while I try to balance things that the playerbase has continually disputed the last 10 years as 'too powerful' and 'overpowered'. Don't beat me up yet.
Wait -700 -800 AC? That seems crazy. I remember being decked to the nines on 25 Dex and all the usual -AC spells plus whatever my class got and I was like -500 -550 max.
How long have I been asleep?
I still think -700 is pretty hard to get to for non crusaders (without leaving gaping holes in other, necessary, areas of defense and offense that is).
-700 to -900...
yeah, I am thinking that's a bad thing.
I've never got to -500 ac 
still such a newb...
There is little point to getting ac that high as there are diminishing returns.
To be fair, diminishing returns aren't the same as *no *returns. Some of the folks that currently have ridiculous -AC are during quite well for it.