THAC0 and AC

[Calerian]

Im new to IW, and also i am relatively new to this game. I find the descriptions in the manual difficult to understand so could anyone put them in terms that a human can understand [img]smile.gif[/img]

[ 01-08-2002: Message edited by: Calerian ]

[Micah Foehammer]

Could you be just a little more specific as to which terms you find confusing?

[Calerian]

THAC0, AC, and the such like, what effects do they have on the game and damage etc?

[daan]

ah,
THAC0 and AC and the like,
they are quite explainable, but may take some writing ....
So before i go dislocate my hand, try searching for related posts with the search-option. I've been here for a while now, and your question has been answered by others AND me in a lot of posts allready.
Though i believe the engine's having some problems lately,
well .. anyway, try to use "search"
(round the top-right of your screen, a little below that)
And write a reply if you couldnt find anything, I'll explain it to you, ... if someone else hasnt allready before that time [img]smile.gif[/img]

You'll find this a very good forum [img]smile.gif[/img] *G*

[daan]

A reply stolen (MUWHAHA, im evil) from -Erydian-
THAC0

THAC0 = To Hit Armor Class Zero
It is a factor that in the D&D and AD&D system (which the Baldur's Gate series uses) helps define your ability to hit an opponent. It is the number that you, an NPC, or an opponent needs to attack an Armor Class zero target successfully. Your THAC0 depends on your class, level, and improves as you attain higher levels.

Basically, whenever you attack in BG2, the game calculates a number based on your THAC0 and your target's armor class, and then generates a number from 1-20. Your target's AC is subtracted from your THAC0 and this number becomes the "to hit" number. If the number generated is equal to, or greater than your "to hit" number, your attack succeeds; if not, it fails. Generally speaking, the lower your THAC0, the better.

Quick example (taken from the manual):

A 3rd-level fighter with a THAC0 of 18 attacks a hobgoblin with an AC of 5. The hobgoblin's AC is subtracted from the fighter's THAC0, resulting in a "to hit" number of 13. In order for that fighter to successfully attack the hobgoblin, the number generated by the game for that attack would have to equal 13 or higher.

If you roll (read: the computer generates) the number 20,
you ALLWAYS HIT !!! No matter what AC your opponent has.
Moreover, you'll do double damage, unless your opponent is wearing a helmet, which averts critical hits.
Also, you ALLWAYS MISS !!! on a roll of 1, no matter what THACO you have, you also get penalty points for your next round.

So NATURAL rolls (natural meaning without bonusses and penalties)
of 20 allways hit, and NATURAL rolls of 1 allways miss.

[Dreamer128]

Calerian! Cool that you joined up! Its me, Velkyn!

[Kaz]

Hi Calerian!
Basically, the lower THAC0, the better, the lower AC, the better. THAC0 is chance to hit, AC is chance to BE hit. Um... daan (that is, -Erydian-) explained how it works.

[Micah Foehammer]

Daan, nice explanation.

Thaco will range from 20 (the poorest) down to a low of 1 (without modification). With weapon modifiers, strength bonuses, spell adjustments, it is possible for modified Thaco's to get as low as -10 or lower.

Similiary Armor class will range from 10 (the poorest - basically NO armor protection) to numbers as "high" as -20 (with spell and item modifiers). In Icewind dale, I have seen Armor Classes as low as -25 (!) with spells effects in place.

The confusing thing about THACO and AC is that the lower or more negative these numbers are, the BETTER they are! lol talk about a bass-ackwards system!

For what its worth, this is all based on the 2nd Edition Advanced Dungeon and Dragons system. The 3rd edition turns this around so that HIGHER AC numbers are better than low AC numbers.

[daan]

Well, couldt find any AC-related topics which search, so here we go ..

Now you allready now how THAC0 works, we'll get to the AC.
Where THAC0 determines wether you hit an enemy or not,
Your AC determins wether an enemy hits YOU.

The lower the better, with a BG-max. of -20 (not sure)
It works exactly as in the hobgoblin-example, you deduct it from the enemy's THAC0, and the result is a number which your enemy must minimally roll to hit you.

When i say roll, i mean that the computer generates a number randomly,
i call it roll, because it used to be done by dices. This is also where the words "hitdice", 2d4 1d8 etc. come frome.
2d4 means 2 dices of 1 to 4.
(The computer will subsequently generate two numbers of 1 to 4)

a hitdice is a dice that determines the HP of your enemy. A hitdice has eight sides. For example :
an Umberhulk has 8 hitdice, this means an Umberhulk can have upto
64 hp. His HP-scala ranges from 8 to 64 ( 8x1 to 8x8 )

The mage-spell "Death-spell" kills any creature of 8 hitdice and lower, thus killing any creature that has 64 hp or lower.
Note though, that this spell looks ate the MAX.hp .. NOT at the CURRENT, a 40th lvl fighter with 2 hp left, WILL survive a deathspell, since his MAX. hp is 300 or something.

To wrap THAC0 and AC up:
to see if you can hit an enemy / an enemy can hit you:
DEDUCT his AC from your THACO.
That number you must minimally roll to hit him.
example:

THAC0 = 15 AC = -1
Number you must minimally roll to hit the enemy is :
15 - - 1 = 15 + 1 = 16

( - - becomes + ... a nice way to illustrate this is to say : " Im not, not going to the party, means you ARE going to the party)

THAC0 = -1 AC = 5
to hit number = -1 - 5 = -6

(meaning you will ALLWAYs hit, except if you roll a natural 1)

If i've left out anything, (it's become quite a lot, so i might have forgotten something or misexplained)
plz feel free to say so
Hope this helps [img]smile.gif[/img]

[daan]

lol, quite a lot of replies while i was typing,
well, that oughta satisfy your curiousity

Indeed you should thank -Erydian- not me Micah, but thx anywayz

(P.s. that last explanation WAS all mine * Daan feeling proud* )
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