You can now set classes for mobs. Mobs flagged as that class will act appropriately. Invokers will only cast invoker spells. Paladins will bash and heal. Anti's will cast tazrik's, unholy on themselves as well as kicking and other fun happy stuff that anti's do. Every class in the game has their own set of spells and actions that they'll do. Here's the numerical listing of the classes. These are the actual values, NOT bitvectors, and they are not additive, that is, you cannot multiclass with this value:
| CLASS_NONE | 0 | *CLASS_THIEF | 13 |
| CLASS_WARRIOR | 1 | *CLASS_ASSASSIN | 14 |
| CLASS_RANGER | 2 | *CLASS_MERCENARY | 15 |
| *CLASS_BERSERKER | 3 | CLASS_BARD | 16 |
| CLASS_PALADIN | 4 | CLASS_PSIONICIST | 17 |
| CLASS_ANTIPALADIN | 5 | CLASS_LICH | 18 |
| CLASS_CLERIC | 6 | CLASS_ENCHANTER | 19 |
| *CLASS_MONK | 7 | CLASS_INVOKER | 20 |
| CLASS_DRUID | 8 | CLASS_ILLUSIONIST | 21 |
| CLASS_SHAMAN | 9 | CLASS_BATTLECHANTER | 22 |
| *CLASS_SORCERER | 10 | CLASS_ROGUE | 23 |
| CLASS_NECROMANCER | 11 | CLASS_ELEMENTALIST | 24 |
| CLASS_CONJURER | 12 | CLASS_DIRE_RAIDER | 25 |
The classes marked with a * obviously are no longer in the game, so I won't bother to write a routine, with one notable exception. Sorcerer mobs will still go back to the standard HAS_MU spell routine which you may want to keep in mind.
As a recommendation before you set mages: Invokers are all offense. Enchanters are all defense. Much like PC's, these alone aren't that great, so you may want to either group them together, or just set 'em as sorcerer or put nothing and just the standard HAS_MU.
The old act flags (HAS_WA, HAS_CL, HAS_MU, HAS_TH) will still work, and I encourage you to use them in conjunction.