Back in the day when I used to mud on Aardwolf the class system was relatively straightforward. You chose a class when you first started and leveled up to the max level of 200. Once there you could do 'end game' stuff or you could start over back at level 1 with a second class. This time through you'd have all of the abilities of both chosen classes and would need more experience for each level to compensate. You could keep repeating every 200 levels. Restart at level 1 with a new class. Once you had all 7 classes at max level you could stop for end game stuff or you could start over at level 1 of just a single class again, but with extra powers. (Some bonus stats and you got to use spells and wear gear 10 levels above you.) You could repeat this up to 10 times! So much leveling!
Which order you chose the classes didn't really matter. Thief/warrior or warrior/thief were just as good at fighting as one another. I can only remember three ways in which your first class mattered... That was the class you represented in class wars. There was one zone with a room for each class and you could only explore the room for your class (which meant you couldn't explore the whole zone until you'd completed 6 entire tiers of leveling and had started in on the 7th). And your displayed name was a function of your first class and your tier number.
Despite that I can remember staying up late debating the 'right' order to choose the classes with Byung and Tom. You really wanted to be a mage because they had the best damage spells. Thieves had the best opening round with backstab, especially when you had high level weapons. Warriors had the best auto attack damage. Clerics were the best healers, and had great buffs. Psionicists were almost as good as mages at doing damage and brought a bunch of utility and more buffs. Paladins were worse than clerics at healing, and worse than warriors and fighting, and worse than psions at damage and buffs. A fine first class, but once you had 3 classes you really didn't want paladin to be one of them. They did have a couple unique buffs though, so they weren't terrible. Rangers were terrible. The only thing they had going for them was the ability to skin the corpses of every monster you killed which would give you an item with random stats. If you got lucky you could make best in slot gear for several slots at every level. But you were so bad! So there were interesting decision to make while leveling based on what combo you wanted at each number of classes. Mage/thief/warrior/cleric/psion/paladin/ranger may have been 'best', but there was definitely debate to be had. It looks like Byung's last setup was thief/psion/mage/warrior/cleric/ranger/paladin!
When I stopped playing I was midway through my 4th tier. I don't even remember what my first 3 primary classes were but I know I chose different ones because I wanted to explore that entire zone. This time around I was a paladin because the display name was slayer and one of the available races is vampire. So I was a vampire slayer. Woo? And I had to get paladin out of the way at some point!
Things have changed significantly since then. They decided they didn't like that all characters with all 7 classes were pretty much identical and looked for a way to shake things up a little. The solution they came with was to make your primary class much more impactful. Each class now has a few spells/skills that can only be used if you have the right first class. Many of the other skills which carry over are significantly more powerful with the right primary class. For example, I have thief as my third class so I have access to the backstab skill. But I don't have access to the enhanced backstab skill as only primary thieves get that. Also, my backstab is worse than a thief's backstab would be. Right now I seem to be backstabbing for around 12% of enemy health. I'm just guessing here, but I bet I'd be doing more like 40% if I was a primary thief. On top of that change, you also get to pick a subclass for your primary class to get even better at something they do. I appear to have chosen to be a guardian which gives me improved safeguard and rescue abilities in order to protect other people in my group. I bet it's a useful subclass for endgame PvPing, but it's absolutely worthless for leveling and questing. If I was a thief I could subclass into assassin to do 25% more damage on backstab. That's probably 10% off the health of every monster I engage on instead of the nothing I have now!
Because they made this change they've granted everyone the ability to change their primary class once for free. You can also pay quest points to change again after that. This means exploring that one zone is a lot easier, and it means I could switch up to something better for more power. (I've also already visited the paladin specific rooms in that zone, so switching out for free makes a lot of sense regardless.) The way it works means if I switch one of my current classes in as my new primary class I end up just swapping and keeping paladin. So I can be a thief/mage/paladin or a mage/paladin/thief or I could throw paladin away entirely and be something like warrior/mage/thief.
I wish I could remember what classes I've already done for that zone. Wait! I have random logs saved from various clan applications over the years... YES! Tier 1 I was a ranger (got that out of the way early) and tier 2 I was a cleric. I'm 95% sure my tier 0 was mage. So I still need to make my primary class thief, psion, and warrior. But I can do that for a bunch of quest points if I end up exploring all the other zones and really need to get the last few rooms in this one. So probably what I should do is pick the primary class/subclass that I actually want and maybe use exploring as a tiebreaker.
Paladin unique abilities: test of faith (chance of extra attacks that I haven't been using because I didn't know it existed), call upon faith (a big self buff spell), divine faith (a less big buff spell), terminate (a damage spell that can instantly kill enemies at 15% health or less), apocalypse (a high level damage spell), heavenly balance (a high level damage spell of a different damage type).
Paladin subclasses: guardian (group tank), knight (charge ability), avenger (PvP damage buff), inquisitor (bonus damage with whips, a debuff, and an interrogate ability of some kind).
Thief unique abilities: enhanced backstab (2 more stabs per backstab), knife fighting (bonus damage with daggers), kobold stench (low level attack skill/debuff), spiral (high level big damage skill).
Thief subclasses: assassin (5th backstab attack, reduced lag on backstab, stalk ability to ambush people in PvP, dex/luck buff, strangle lag removed), ninja (can backstab in combat, extra damage with hand to hand, extra damage when not dual wielding, dex/luck buff, extra damage on every autoattack, impacted less by blind, stealth ability to ambush in PvP), bandit (dex/luck buff, extra gold earned, ability to steal items sometime when buying from a shop, the ability to flag a noPK room as temporarily PK, the ability to sell extra items, a chance to make extra money when selling items), venomist (dex/luck/con buff, a chance at 25% damage ability, off the GCD damage amplifying debuff, extra damage on autoattacks, different extra damage on autoattacks, different extra damage on autoattacks and backstab).
Mage unique abilities: low level damage spell, mid level damage spell, best high level damage spell, awesome self buff.
Mage subclasses: elementalist (ability to buff an elemental damage type to do more damage, ability to take less elemental damage, three new elemental damage spells), enchanter (ability to enchant gear better at max level, small stat boost), sorcerer (buff to do more damage with spells, debuff to make the enemy do less damage, different debuff to make the enemy do less damage, new damage spell, improved web for PvP, debuff to reduce enemy luck).
Warrior unique abilities: fifth autoattack, sixth autoattack, toughness buff, shield block (only warriors can really use shields well, apparently), attack skill with a stun component, chance on every hit to instantly kill the target.
Warrior subclasses: barbarian (extra damage with fists, extra damage when not dual wielding, buff to do extra damage with fists), soldier (ability to block exits in PvP, easier dual wielding), berserker (enrage ability to take and receive double damage, different ability to take and receive extra damage), blacksmith (ability to temporarily buff weapons, ability to convert weapons into hammers, ability to use hammers, do extra damage with warrior stun ability when using a hammer).
Psionicist unique abilities: combat mind (buff spell), willpower (defensive buff spell), pyromania (high level damage spell), desolation (another high level damage spell).
Psionicist subclasses: empath (experience gain buff, ability to know who killed monsters in nearby rooms), mindflayer (off GCD debuff to lower enemy autoattacks per round, off GCD PvP debuff to lower enemy skill in an ability), navigator (ability to create a beacon that can then be teleported to on global quests, ability to lower GCD on all spells, ability to create a different beacon that can then be hunted, ability to block areas from showing up in quests and campaigns, ability to doorway to max level characters, ability to make unique and awesome chaos portals), necromancer (ability to see what monsters are flagged undead, damage spell that does a lot extra to undead, higher level damage spell that does a lot extra to undead mobs and vampire players, yet another higher level damage spell of the same ilk, an off GCD spell that turns a mob undead, an ability to force a zone to immediately repop with the monsters that repop being undead (24 hour cooldown), ability to know who killed monsters in nearby rooms).
Cleric unique abilities: rally (offensive/defensive buff spell), pure faith (huge self buff), party sanctuary (sanc the party, worthless to me but could be awesome for starting characters?), healing touch (heal only used on party members), regeneration (big heal spell), voice of god (high level damage spell).
Cleric subclasses: priest (ability to enhance hallowed lights, buff to increase healing done to a target, ability to spend money to change align to max good, ability to turn a PK room into a noPK room, group buff to reduce shadow, negative, and desecration damage), martyr (group buff to negate berserker damage buff, self exp buff, massive group heal that hurts self, AE damage spell that hits all enemies and the caster, something about blessed weapons not being owned?), oracle (ability to determine what key opens a door, ability to detect PvP ambushes, ability to detect an unexplored room (what?), ability that tags campaign mobs), harmer (buff that lets you ignore sanctuary!, debuff that reduces incoming healing, ability to sacrifice health to change align to max evil).
Ranger unique abilities: gaias revenge (extra auto attacks per round), wolf spirits (big self buff), call lightning (big damage AE spell that only works outside in a storm), tame (ability to turn an aggressive mob nonaggressive), energy ball (self buff), eruption (high level attack spell).
Ranger subclasses: hunter (improved hunt skill, ambush skill for PvP/gquests, ability to hunt a pet, archery skill to attack from other rooms, self buff to shoot better, immune to other ambushes), shaman (self buff to hit more often, ability to choose damage type of gaias revenge, self buff to hit harder, ability to force a zone to repop once every 24 hours), crafter (ability to add extra stats to a skin, ability to merge worthless chaos portals into a new blank one, ability to generate resists on skins).
Well... That's certainly a lot of variety. Some subclasses have extra damage, some have extra experience, some have PvP applications, some have utility. I really want to be a navigator at some point, but I feel like I don't know enough about the new zones to make good use of it for now. It's also really not clear how many other abilities are nerfed if they aren't from your primary class like backstab and the like are.
What I do know is I still have a pretty good selection of powerful weapons, and I do need to be a warrior at some point, so I think I'm going to give that shot. On the plus side that also lets me keep mage and thief so I will still get to backstab and cast reasonable nukes. I don't know which subclass I want though... They all seem bad. The power I want of the warrior is from the extra attacks per round that all primary warriors pick up. I guess the ability to do and take double damage is probably the best? I can just drink more potions, right? Right!