THAC0

[Drohem]

When did the term THAC0 start to be officially used in TSR materials?

What was the first product that used the term?

[aldarron]

interesting discussion on that is here www.freeyabb.com/trolllordgames/viewtopic.php?mforum=trolllordgames&t=4615&postdays=0&postorder=asc&start=15&mforum=trolllordgames
The short answer is that it was in the DMG p 196-215.

Presumably it was one of Gygax's ideas, but who knows, maybe it is as old as the system itself.

[calithena]

In the field: tables dominated for a certain period.

Gamelords introduced their system, which included HACO, in the early eighites.

THAC0 as a defined quantity only emerged with TSR products after the Gamelords innovation.

T. Foster and some other folks over at the K&K have observed that once you have THAC0 there's no reason not to go to 3e style AC. From a purist's point of view there are advantages to the table approach and advantages to the number calculation approach, but no particular reason to adopt the intermediate approach of late 1e and 2e.

Or anyway that's one thing you could think about this.

[Drohem]

Oct 21, 2009 17:03:13 GMT -6 aldarron said:

interesting discussion on that is here www.freeyabb.com/trolllordgames/viewtopic.php?mforum=trolllordgames&t=4615&postdays=0&postorder=asc&start=15&mforum=trolllordgames
The short answer is that it was in the DMG p 196-215.

Presumably it was one of Gygax's ideas, but who knows, maybe it is as old as the system itself.

Thanks for the link.

I was chided, in good fun, on another site for recommending that a space for THAC0 be added to a 1st AD&D character sheet being designed by a poster. I was told that THAC0 was purely of 2nd AD&D, and that the appendix in the 1st AD&D DMG didn't make it part of 1st AD&D 'core.'

This got me wondering about it since I have memories of using THAC0 back when we played 1st AD&D, and have it written on some of my 1st AD&D character sheets. I just knew that we used that term long before 2nd AD&D came along in 1989.

[Matthew]

Oct 21, 2009 21:31:01 GMT -6 calithena said:

T. Foster and some other folks over at the K&K have observed that once you have THAC0 there's no reason not to go to 3e style AC. From a purist's point of view there are advantages to the table approach and advantages to the number calculation approach, but no particular reason to adopt the intermediate approach of late 1e and 2e.

There are reasons to continue with the normal armour class system when using THAC0 in lieu of tables, principally being the continuity of negative and positive modifiers [i.e. everything is calculated from the attacker's point of view, positive modifiers to armour class or hit rolls are always good, negative modifiers are always bad].

Gygax mentions in the DMG (p. 164) that the only reason he did not switch to an ascending armour class system was "for the sake of continuity and familiarity" with the original Dungeons & Dragons game.

[Ghul]

It is with this "...continuity and familiarity" that I feel at home and comfortable. I suppose many at this forum would agree.