THAC0 Tables

Different types of character and creature have different THAC0 they may consult.

Which Table To Use?

A character uses the best THAC0 table they qualify for by their Level or HD. For example, a Level 9/11 Fighter/Thief would gain a THAC0 of 12 from Fighter and only 15 from Thief. As such, they use 12 for their THAC0.

Classless Characters (and Pseudo-Class Characters) use the Creature THAC0 table with either their Hit-Dice or Level.

If they later take a Class, they use either their THAC0 from HD on the Creature table or what they gain from Class levels, whichever is higher. For instance, a 12-1 HD Hill Giant gains 9 THAC0 by default. If the character took the Fighter Class and gained 5 levels, this would not increase their effective HD by 5 on the Creature Table, granting them an effective HD of 17 and a THAC0 of 3. Instead, it would allow them to choose between THAC0 16 (Level 5 Fighter) or THAC0 9 (12-1 HD Hill Giant).

THAC0 Tables

THAC0 Tables are divided between the Class Groups - Priest, Rogue, Warrior and Wizard. Furthermore, a Creature table grants a base THAC0 to creatures based on their HD, reflecting the power of stronger creatures.

THAC0 Tables
Level/HD	Priest	Rogue	Warrior	Wizard	Creature
0	20	20	20	20	20
1	20	20	20	20	19
2	20	20	19	20	19
3	20	19	18	20	17
4	18	19	17	19	17
5	18	18	16	19	15
6	18	18	15	19	15
7	16	17	14	18	13
8	16	17	13	18	13
9	16	16	12	18	11
10	14	16	11	17	11
11	14	15	10	17	9
12	14	15	9	17	9
13	12	14	8	16	7
14	12	14	7	16	7
15	12	13	6	16	5
16	10	13	5	15	5
17	10	12	4	15	3
18	10	12	3	15	3
19	8	11	2	14	1
20+	8	11	1	14	1