Here are some of my thoughts and observations on each of the classes in Wizardry: Labyrinth of Lost Souls.

Fighter: Decent early game class, but suffers from a lack of equipment later on. The main advantages of this class are the low barriers to entry (only 12 STR and no alingment requirement), the high HP per level (which isn't as important as the character's race), and the fact that fighters level faster than any other class (even fasther than thieves). Their special ability Trick Attack requires an extra round to focus, but hits twice as hard. I haven't tested this, but it *might* be useful against higher defense enemies, but otherwise this ability just doesn't seem that useful.

Mage: Learns every mage spell, and gets the Magic Boost ability. You have to Focus for one round, but if you ambush the enemy, you can use the surprise round (where you wouldn't be able to cast spells). Magic Boost might seem as useless as Trick Attack, but it actually does have some nice uses. In particular:
* As I just said, you can Focus in the surprise round, when you wouldn't be able to cast a spell.
* Magic Boost works on priest spells. Create a priest, then change them into a mage, and after learning Magic Boost, you can now boost priest spells this way.
* By using Magic Boost wirh priest spells, you can increase the power of healing spells. The tactical use is unfortunately limited by the existence of spells that can fully heal (even the entire party), but it is an interesting strategic option (especially if you already have the boost ready and don't need to blast the enemies), and does feel like a bit of a missed opportunity.
* Magic Boost works with status spells. Try it with Cloud of Death for a reliable group targeted instant death attack! (Some enemies are immune, but in the late game where damage spells tend to be a bit weak, this is a great way of taking care of many enemies, particularly before you get top-tier weapons.)

Priest: Learns every priest spell, and is the fastst for learning priest spells not on the lord list. Exorcism is a good way to speed up combat with undead enemies, but from what I've read you only get half the experience. I don't know how well it works for item drops (if it works well, priests might be good for a couple of the more annoying (and unnecessary) side quests).

Thief: One option for dealing with chests. Chests are not as important in classic Wizardry, as you can get items without chests, and it's rare for chests to have anything interesting. (I did find a Lord's Book in a chest, however.) Also, particularly with healing magic being so powerful, many of the chest traps are non-issues, and Divine Trap lets you identify traps without issue. On the other hand, a thief's backstab ability (requires hiding first) allows for earning a little extra money (especially if you can backstab a dragon), and there are a few locked doors that you will need to pick (though I haven't checked to see if any are required). Even with backstabbing, however, thieves are still not the best class for earning money.

Bishop: A *really* good class. Learns every spell in the game, learns mage spells at the same rate as a mage (aside from needing more XP to level up), eventually learns all the priest spells (but gets them more slowly than a priest or lord), and even gets the game-changing Magic Wall ability at level 16. That ability is so useful that you might find yourself ignoring the bishop's spellcasting ability in the later levels (though it might be interesting to challenge yourself to not use it). The Appraise ability, which lets you identify items for free, is a great way to earn money; one strategy is to appraise items you find, sell them, and have a mage or bishop tithe all the money you get; this will allow you to get game-changing spells like Emergency Exit, Free Warp. and NAL Burst earlier, saving travel time and making it easier to get to the point were you can level new characters quickly. In any case, unlike most other Wizardry games, bishops are actually good for more than just identifying items this time around.

Samurai: Fighter-type with mage spells. Unfortunately, the samurai only learns some of the spells, missing all the non-combat spells that you'd want on a front liner, as a samurai may very well be too busy attacking to use magic. The samurai's special ability lets them hit a group, which is really useful if you get a good weapon. There are some really good weapons for the samurai, but they're late game weapons and tend to be pretty rare. In any case, this is the best offensive class in the long run, but might be lacking before then.

Lord: Fighter-type with priest spells, and a Huge Shield ability that draws attacks to the lord. The special ability is really powerful when combined with spells like Evasion Field (I believe it's called Hard Guard in the Japanese version; Evasion Field describes its effect better, but its use of the term "Field" is contrary to the convention other spells follow where "Field" means "hits group of enemies"). The interesting thing about Lords is that they actually improve faster that other characters; while they only learn half the priest spells, they learn them faster than a priest, getting access to 6th level spells potentially as early as level 7. So, while a Lord won't learn Healing Aura, they will learn the more powerful Healing Wind around that time. Lords don't get the full heals, however. This early growth is also mirrored in equipment; you can get some nice armor as early as Shiin B4F if you're lucky, and the Odin Sword, while not as powerful as the samurai's katanas, is much easier to get. The problem, however, is that the lord's stat requirements make it difficult to get one early.

Ninja: Rather disappointing in this game. Their fighting ability is not much better than a thief; they can use shurikens, but that's about their only real advantage over a thief in the weapon department, and shurikens are not strong enough to be useful late game. They can Assassinate after hiding, but that instant death attack may not be as useful as stealing money. They can act as thieves when it comes to doors and chests (though some say they're less effective), but that's all they really have to offer. In particular, ninja are not the fighter/thief hybrid they were in classic Wizardry. (Also worth noting that, unlike Wizardry 6-8, ninja don't get any magic, either.) All this for having the most stringent attribute requirements of any class, and the slowest leveling.

I know this is really old, but in case anyone else finds this: the fighter's Trick Attack power actually seems pretty good. You give up one turn and, in exchange, on the second turn the fighter makes THREE separate attacks against valid targets in one group (separate attack actions, not just "attacked three times" like you do with a fast weapon). Basically, you can attack 1.5x as often using trick attack.

However, the trick attacks will not cross groups, so if a group is left with just a single foe then some of the attacks will be lost, etc., and you miss out on the opportunity to eliminate a foe in the first round. It isn't worth using all the time, but for me it's an always-use on surprise rounds and against particularly tough foes.