the Prestige of the PRC

[Vilehelm]

Now, I have read for months on these boards. I've read and enjoyed the optimization forums of WoTC also, and while I do understand the benefits of PRCs and their appeal, I can't help but wonder...

Where has the prestige of PRC's gone?

I see statements such as "there is no reason not to PRC out of a class" I fully understand from an optimisation point of view that a PRC will always be a better option, but who plays like that in reality? Who plays with the entire list of PRC's available for their characters?

When reading the DMG, I see the advice that prestige classes are DM option only, and should be carefully selected and/or created to fit your campaign. While in my own campaign I carefully monitor what PRC's I make available for my players and they like it this way. Getting a PRC in my campaign is a sign you are accomplishing something, not just pre-planning your character up to level 20.

I am fully aware that PRC's have requirements that players should be aware of so thay can build their characters to fulfill thrm. This can be easily remedied with a bit of retraining, however.

Now, I am no basher of the PRC. I find them a great idea. I just wonder why there have to be one thousand of them, for every minor variation in class possible. It's often said that they grew out of the 2nd edition character kits (which are basically variant classes), but in 3.0 and 3.5 we also have variants and substitution levels which accomplish the same thing.

Aside of some focussing issue I have with them, I am fully supporting their existence. It's mainly the availability which I am questioning here.

Who plays with PRC's as actually prestigious classes that are rare and one has to fight/struggle/adventure for rather than simply a "class with requirements"?

[Skjaldbakka]

Who plays with PRC's as actually prestigious classes that are rare and one has to fight/struggle/adventure for rather than simply a "class with requirements"?

I don't. I see classes as ways to get my PC to do the kind of things I want him to be able to do. In short, I view the vast majority of classes as an OOG concept.

My order of operations is one of two things when making a character:

Oooh shiny PrC --> create 20 level progression --> find a game to play it in --> determine actual starting level --> shoehorn what I can into starting character --> Create backstory/personality based on build choices

OR

Come up with concept --> spend the next several weeks until the game starts toying with different character builds that represent that concept --> work out any missing details before game starts -->begin game --> toy around with different ideas for the next several levels

[Reinboom]

I don't particularly like "Prestige Classes" or "Classes" to represent a character -at all-. I HATE more than a core amount of fluff associated with a prestige class unless it's absolutely necessary. I still like the class/prestige class system, however, just not the fluff supporting it.

To me, the names mean nothing. What defines a character is what they do, how they act, and how they show their capabilities. A prestige class isn't something you strive to reach, to become. It's what you already are, and you just getting better at it. Perhaps with a little bit more focus. To me, someone isn't a Druid who becomes a Master of Many Forms, they instead are... what they wish to be with that. A barbarian wild man who has reached such a primal state as to shape between the creatures of which they came from or a slick sly shapechanger, able to disguise, and take the abilities of, any form.

I am fully aware that PRC's have requirements that players should be aware of so thay can build their characters to fulfill thrm. This can be easily remedied with a bit of retraining, however.

The retraining rules weren't introduced until PHB2. Not everybody has access to the PHB2, nor is it OGL.
With that aside, a few prestige classes representative of fluff just doesn't make sense to me...
Look at the archmage, for example. The requirements.
The spellcasting requirements? Great, that works perfectly. The skills? Not too fond of, but, I understand them. You need a focused knowledge of the arcane and must be well worked with the effects of spellcrafting.
The feats? Bwuh? How does being focused in two different schools make you any more of a candidate of being a archmage than, say, someone who was capable of a ton of spell alterations (metamagic)? Easy: Balance and cost.
To me, Prestige Classes aren't a fluff. They are mechanical. Purely. Completely. The fluff is only there to make them look nice. If they weren't, the costs into them wouldn't be mechanical.

Now, a bit of slightly unrelated rant:

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I don't particularly understand the idea of a lot of people of "Oh! But you are an optimizer, and bad role player because you preplan out your character!", because, well... so did they. They chose at least the first level, and then built their character to it (or vice versa). Why can't someone do that 20 times over?

[Dhavaer]

I agree with SweetRein. For the most part, classes are an OOC concept. This doesn't hold as true with class that have very distinctive abilities ('wizard' will probably be an IC concept that matches the OOC concept quite accurately) but classes like Rogue, Fighter, Warblade or Scout are generic enough to be anything that matches their skill set.

[Tengu]

I see prestige classes as a good way to give characters more distinct abilities than the default, generic things normal classes can do. Of course, it's still inferior to games that don't feature classes and offer you more options to make your characters diverse, bit it's a big step forward from AD&D's "I'm a warrior and the only differences, crunch-wise, between me and another warrior at the same level are the stats and what weapon I use". Feats do the same, but the abilities they give you are usually less prominent than PRCs' features.

SweetRein:

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I think they're sour grapes. They cannot stand that someone can make a character who's much better at what it's supposed to do, so they desperately try to come up with something they're better in, and make up lies such as "if your character is good mechanically it's because you pay all attention to mechanics and no to actual roleplaying!!1one1!" - lies they quickly start to believe in themselves.

[KIDS]

While I agree that classes (all) should be prestige in terms of preserving their basic tenets such as codes of conduct or roleplaying basic requirements, ultimately you must realize that people play characters that are modeled by using classes/prestige classes and that classes are an OOC concept. Unless it's some guideline in the PrC itself, you should not be the one judging "hey this PC isn't as devoted to travelling as I think he should be a Horizon Walker" - it is kind of rude and infringes on the basic individuality of the game.

[Skjaldbakka]

@Tengu

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Actually, as with most stereotypes, the powergamer/roleplayer dichotomy is spawned through observation. The human mind tends to remember extremes much better than it does things that are in the median. The end result? Associations between powergaming and bad roleplaying (because powergaming is most apparent(and most aggravation-inducing) in people that are bad roleplayers). Similarly, you comment about sour grapes from people who claim good roleplaying skills because they lack the good general rules knowledge it takes to make a competitive character.

I have found that the characters I play that have good, well-rounded backstories and well developed personalities tend to be more survivable than characters that I play to "see what I can do with X idea". Perhaps because I care more about the former, and develop an emotional attachment to the character and his goals. I never think of a character as a "class XYZ", unless that character is more of a thought/build experiment than a PC I care about.

[Rad]

I think that classes should have no fluff as well: they are just a set of abilities that I use to represent my character; the concept here is the real thing; what I put on the sheet is just its implementation.
Some of the abilities that you gain need a GdR explaination (you are a renegade mage! how can you access the spellpool? Why does your aasimar have DR/cold iron?).

Players do work with roleplay to attain goals, such as being admitted to the Holy Order of the Mystic Rose, being elected Archmage over the Islands; and so on. I like to keep the mechanical aspects of the PG separated from all of this though.

[deadseashoals]

IMO, if class and feat selection was truly meant to be a role-playing aspect, rather than just mechanics, they shouldn't have made the system so damned complicated. It's basically impossible to express your character's growth organically through his feat and class/PrC selection in any meaningful way without completely gimping your character. Because this is the way the game is set up, I don't think it's really fair to impose things like "why is your monk taking a level of Fist of the Forest, he's never even been outside."

[Quietus]

For all of you that are complaining about the fluff attached to PrC's... I ask you to put some thought into what would happen if that fluff WASN'T there. Wouldn't they become extremely dry to read?

Archmage : This class expands greatly on the options available to an arcane spellcaster, at the cost of having less spells per day.

Frenzied Berserker : This class presents characters already capable of raging with the ability to become even MORE angry, but become unable to distinguish friend from foe.


And so on. The mechanics are what drive the classes, certainly, but the fluff is what makes them interesting to read. And as has been pointed out many times before, the fluff can be changed if you want. Fluff is a suggestion, it's what they originally intended for the class, but it's NOT a straitjacket. The mechanics? Generally, yeah - they're going to stay more or less the way they are. But the fluff can be changed without altering the class at all, with a couple exceptions (FB among them).

[TimeWizard]

I love and support PrCs. Unlike base classes, a Prestige Class is an in game idea; you are an Assassin, or Archmage. It's what gives them prestige.

@ Tengu and SweetRain: I dislike the idea of a 1-20 character plan because I feel that it does not leave suitable room for a character to grow with the change of the game. I beleive more in general ideas and concepts so my character can reflect change in the story. But I usually keep an idea of how I want to go, like Druid/MoMF. I just don't plan it out til I get there... because I have more fun that way.

[Reinboom]

For all of you that are complaining about the fluff attached to PrC's... I ask you to put some thought into what would happen if that fluff WASN'T there. Wouldn't they become extremely dry to read?

Yes, it would be sort of dry. The fluff presented is a good thing it's there at all... however... I hate the idea of it being the "prestigious goal", but rather just an expansion on what you already are.

Archmage : This class expands greatly on the options available to an arcane spellcaster, at the cost of having less spells per day.

Aye, yes, that's what the class does. Not why I picked on it though, the requirements are. It's a class that expands on options, yes. But it's the intro that I noted. I have nothing against the archmage though, just dislike those who use "In order to be an Archmage you must take levels in Archmage." Simply because, as the rules are currently, you just can't become an Archmage organically. You -have- to plan.

Now, I have no issue with the fluff or mechanics (er, except the mechanics of a couple classes...), just, I don't use the fluff. It makes no sense to me to. That's just a guideline to me, or their idea of how to use this set of mechanics. Not a rule. And I can't stand those who try to enforce the fluff.
For this same reason, I hate role play requirements as well in prestige classes, they just make it that much worse by trying to blur fluff and mechanics. I also HATE alignment requirements. (The biggest example issue for me is, "I want to be a telepathic sorcerer... but I can't grab mindbender because I can't be good... why can't I be a good telepath?")

@TimeWizard
I plan almost all my characters 1-20. I get a lot of fun out of planning actually. I don't live by it, however (I rarely do) and I make a lot of divided options in the plan in case my character decides to take a different route.
More or less, I make a path that splits into a dozen roads, all of which I can healthily travel instead of not planning and following the blind path of a thousand roads, many of which restrict and limit me.

[hamstard4ever]

The decision to say "X is a feat available to anyone, Y is a substitution level ability available only to dwarven fighters, and Z is a prestige class ability limited strictly to ordained members of the Epileptic Order of The Dancing Yellow Zebra" often seems to be made on a completely arbitrary basis. Mechanically, the prestige class system offers a decent framework for customizing your character's abilities, so why not take it and use it as such?

I think the PRC concept does have some mechanical limitations, mind you. In particular, the idea of suddenly gaining a whole new ability progression that appears at level 6 and abruptly stops at level 15, like many PRCs do, really overcomplicates game balance issues. But a lot of PRCs revolve mostly around advancing existing class features with some variation, very much resembling character kits, and I think this part of the system functions very well. It gives greater freedom in character options while still retaining an element of organic growth and balance, which tends to be lacking in alternate class features and substitution levels.

[SmartAlec]

I'm all in favour of Prestige requirements. They make great plot hooks!

e.g. Weapon Master:

"To attain Mastery of the Sword, young warrior, you must seek out the ancient Swordmaster, Enpi-Ze of Plo'tuuk, who is said to dwell upon the high peaks of the Fartothesouth Mountains... and convince him to train you in the ancient ways."

Because, really, while having the freedom to plan out a character without restriction appeals to a certain type of person, if you can take a game mechanic and turn it into an entertaining quest for all, that's much better all-round.

[tyckspoon]

I'm all in favour of Prestige requirements. They make great plot hooks!

e.g. Weapon Master:

"To attain Mastery of the Sword, young warrior, you must seek out the ancient Swordmaster, Enpi-Ze of Plo'tuuk, who is said to dwell upon the high peaks of the Fartothesouth Mountains... and convince him to train you in the ancient ways."

Because, really, while having the freedom to plan out a character without restriction appeals to a certain type of person, if you can take a game mechanic and turn it into an entertaining quest for all, that's much better all-round.

Assuming it is in fact an entertaining quest for all. It's asking the entire group to go along on a quest for the benefit of one character, which can't be guaranteed to be fun for all of them. And that's ignoring the possibility of conflicting scheduling; what do you do if at the same level, you have another character who needs to go train with the Horse Masters of the Wayupnorth Plains, and a third who would prefer to stay in his nice comfy city during this period where the group doesn't have any pressing mission and do some crafting?

[Crow]

I'm all in favour of Prestige requirements. They make great plot hooks!

e.g. Weapon Master:

"To attain Mastery of the Sword, young warrior, you must seek out the ancient Swordmaster, Enpi-Ze of Plo'tuuk, who is said to dwell upon the high peaks of the Fartothesouth Mountains... and convince him to train you in the ancient ways."

Because, really, while having the freedom to plan out a character without restriction appeals to a certain type of person, if you can take a game mechanic and turn it into an entertaining quest for all, that's much better all-round.

This is what I do. It also makes for a good quest when players aren't sure where they want to take the plot next. I almost never allow somebody to take a prestige class without at least some signifigant RP investment.

[SmartAlec]

Assuming it is in fact an entertaining quest for all. It's asking the entire group to go along on a quest for the benefit of one character, which can't be guaranteed to be fun for all of them. And that's ignoring the possibility of conflicting scheduling; what do you do if at the same level, you have another character who needs to go train with the Horse Masters of the Wayupnorth Plains, and a third who would prefer to stay in his nice comfy city during this period where the group doesn't have any pressing mission and do some crafting?

As for the entertainment - that's my job.

As for the party sorting out their own scheduling - that's their job.

As for the party not pulling together and refusing to help out a fellow comrade 'because there's nothing in it for them' - what sort of players are you playing with?!

Seriously, if the party's reached the point where one member is thinking of taking a prestige class, then they've been adventuring together for a while. If they haven't bonded enough by now to be prepared to help out One of the Team when he or she needs it, they never bloody will. In my book, I call that a 'failed campaign'.

EDIT: And if they don't trust me to do everything I can to make things fun for everyone, then I've failed.

[de-trick]

For me I try to have a idea of What my character is. The build I make is a very veg build changes can be made easily. Like I could plan to take x feat, but I need x feat to survive

[The_Snark]

As for the entertainment - that's my job.

As for the party sorting out their own scheduling - that's their job.

As for the party not pulling together and refusing to help out a fellow comrade 'because there's nothing in it for them' - what sort of players are you playing with?!

Seriously, if the party's reached the point where one member is thinking of taking a prestige class, then they've been adventuring together for a while. If they haven't bonded enough by now to be prepared to help out One of the Team when he or she needs it, they never bloody will. In my book, I call that a 'failed campaign'.

EDIT: And if they don't trust me to do everything I can to make things fun for everyone, then I've failed.

The only problem is that this is game- (and DM-) specific. Sure, you're able to work it into your campaigns, and able to make it fun for the whole party.

On the other hand, imagine a war campaign, in which the party is desperately trying to stave off an overwhelming invasion. One of them wants to be a Weapons Master/s, but are any of the party going to want to travel to the Mountains of Fartothesouth and train under the gurus there while the war's going on? No; that would be absurd, and none of the rest of the party should be putting up with it IC.

It also means you're pidgeonholed into whatever fluff they've given you. Sometimes, that's fine; a Rainbow Servant really ought to be associated with couatls, a divine champion class ought to require the approval of the deity (which might be becoming sanctioned by a lawful church, or it could mean an exorbitant sacrifice to the gods of slaughter). On the other hand, let's say I want to change the flavor on...

But the fluff can be changed without altering the class at all, with a couple exceptions (FB among them).

A challenge! I want a frenzied berserker who, instead of being a guy who gets incredibly angry, is possessed by the spirits of the dead in battle. They don't recognize friends, though they'll kill people attacking them first, and because they're half-caught up in their own memories of battles, they continue to attack something as long as they possess the character. They also don't care much about the state of the character's body, hence the deathless frenzy. It actually works really well, mechanically and thematically.

If the class said that you must have joined an elite order of Viking-types by putting flight to an entire village by yourself, that wouldn't work at all. It's why a lot of people dislike fluff-based prerequisites written into the class. Myself included, because I like coming up with more interesting fluff than being more berserk than most berserkers or hating all spellcasters (Occult Slayer).

On the same tack, this can limit the setting the prestige class is present in. If the Weapon Master must train with an elite order housed in the mountains, what happens when neither mountains nor order are present in your campaign setting? Or if Abjurant Champions were written as the elite guard/soldiers of a particular magocracy, and you're running a game that doesn't have room for a extra, not-really-fleshed-out country?

You end up throwing the given fluff out, usually, unless it's really tied to the class. And at that point, you might as well just be making it up.

Not that making it up is a bad thing! In a land where wizardry is a high art, archmages, incanatrixes, and other arcane classes might be members of specific orders—or you'd at least have to learn from a member of the order, or steal texts, in order to enter the class. I generally find that if you make your own prerequisites, they'll fit into your capmaign setting and your campaign much better.

Many prestige classes really don't need them, though. A doppelganger doesn't really need to join a secret order of shapeshifting or mind-reading warriors to be a warshaper or mindspy; that's just the character experimenting and improving on natural capabilities. There's no reason a character should need to join a knightly order in order to be a knight protecter or cavalier—it's not like every military order hoards secret battle techniques that only people who've joined them can use.

In general, I tend to keep in-game prerequisites light, because I usually don't want my players to go off on sidetracks around level 5 to enter prestige classes, and with most of them, it feels a bit contrived to require that they do something IC for a benefit that's not especially noticeable (many abilities aren't). As long as the player can rationalize it, I'm generally okay with it.

[SmartAlec]

On the other hand, imagine a war campaign, in which the party is desperately trying to stave off an overwhelming invasion. One of them wants to be a Weapons Master/s, but are any of the party going to want to travel to the Mountains of Fartothesouth and train under the gurus there while the war's going on? No; that would be absurd, and none of the rest of the party should be putting up with it IC.

Well, this is where letting the DM know what you want to do ahead of time really comes in handy. So, you want to be a Weapon Master in a campaign centred around an invasion? Well, if you let me know that a couple of levels in advance, perhaps I can bring the Swordmaster to you. Having a famous warrior join the war would be a major plot point, and a PC wanting to train with him would first need to impress him with some epic deeds in battle...

You see what I'm saying here? There's always a way. As long as my players keep me informed about what they want to do, I can build my game around that. And as long as they do that, I can continue to make it interesting.

[Crow]

Well, this is where letting the DM know what you want to do ahead of time really comes in handy. So, you want to be a Weapon Master in a campaign centred around an invasion? Well, if you let me know that a couple of levels in advance, perhaps I can bring the Swordmaster to you. Having a famous warrior join the war would be a major plot point, and a PC wanting to train with him would first need to impress him with some epic deeds in battle...

You see what I'm saying here? There's always a way. As long as my players keep me informed about what they want to do, I can build my game around that. And as long as they do that, I can continue to make it interesting.

Seconded. ;)

[The_Snark]

Well, this is where letting the DM know what you want to do ahead of time really comes in handy. So, you want to be a Weapon Master in a campaign centred around an invasion? Well, if you let me know that a couple of levels in advance, perhaps I can bring the Swordmaster to you. Having a famous warrior join the war would be a major plot point, and a PC wanting to train with him would first need to impress him with some epic deeds in battle...

You see what I'm saying here? There's always a way. As long as my players keep me informed about what they want to do, I can build my game around that. And as long as they do that, I can continue to make it interesting.

This is true. But it's not necessarily the case that all DMs will want to change around their campaigns to accomplish fluff prerequisites (good that you do, but not all of them are that versatile).

And I'm still of the opinion that good fluff is most often invented by the DM/player (who can tailor it to setting, campaign, and character), not packaged with the class.

[Crow]

And I'm still of the opinion that good fluff is most often invented by the DM/player (who can tailor it to setting, campaign, and character), not packaged with the class.

I'll agree with that, and in my case it often applies to the name of the class as well. There aren't any "Purple Dragon Knights" in my world!!!

[Mewtarthio]

And I'm still of the opinion that good fluff is most often invented by the DM/player (who can tailor it to setting, campaign, and character), not packaged with the class.

Yes, but the fluff can also be altered when you insert the fluffy quests. Take your Frenzied Berserker example. You've completely altered the fluff of the class, but nothing prevents you from making a quest tied to the new fluff (say, you must visit a great battlefield and meditate).

[hamstard4ever]

If a player says "Gee, it would be pretty cool if my guy could do X. I'd even be willing to sacrifice a few levels' worth of class benefits and invest in some non-optimal feats and skills for flavor reasons", where X is an ability that is balanced for the character's level, and is something that someone of the character's abilities could reasonably achieve without breaking suspension of belief (at least not any more badly than core abilities)... I really don't see any need to put arbitrary hurdles in their path.

I mean, hey, if room can be made in the plot for an appropriate training montage, then go nuts! It just seems rather silly and arbitrary to absolutely require major quest arcs for every prestige class, though, particularly those represent specialized paths within the abilities that characters already have. I mean, sure, some players want to cobble together strings of several prestige classes with wildly different themes and abilities: "OK, this level I want to pick up shadow powers, and then next level I want magic archery powers, and then the level after that I want holy mount powers, and then after that I want ice powers, then mind control powers and animal transformation powers after that. By that point I'll be able to combine all this stuff to get 20 attacks every round at +90 to attack and damage." By all means, throw in all the arbitrary restrictions you want for stuff like that! But if someone is just pursuing the organic growth of their character's abilities, why bother getting in the way of that?

In summary:
Working major PrC choices into the campaign's plot = good
Absolutely requiring huge epic quests every time a player wants to steer their character's abilities in a slightly different direction = stinky

[Mewtarthio]

I suppose it depends on the PrC, really. If somebody wants to become a Shadowdancer, they'd better have some in-game justification for suddenly gaining access to shadow powers. If they want to become a Thaumaturgist, all they have to do is spend more time studying calling spells.

[hamstard4ever]

Well, yeah, that's what I'm saying. Don't get me wrong, even generic PrCs like thaumaturgist can make good story fodder. It would be natural for a cleric interested in advanced summoning techniques to want to investigate possible sources of additional knowledge on the subject, conferring with more experienced summoners, etc. And we're talking about a relatively high level PC, notable enough to be gaining some reknown as a moderately good authority on the subject of planar summoning magic. All this can make for some very good plot hooks when needed, but there's really no particular reason to strictly require any huge in-character involvement before allowing the PC to take any levels of thaumaturgist--these things will play out just as well, if not better, if done as the PC is progressing through the thaumaturgist class itself. It's reasonable enough to expect the PC to put in some significant in-character work on their path to achieving mastery of their chosen specialty, but making them jump through hoops to merely start exploring it just seems arbitrary.

Even for a more unusual PrC like shadowdancer, this can still conceivably work if the PC actually fits. If a plain 7th level rogue says "OK, I train really really hard at hiding, now I have magical superhuman powers of hiding!" I might roll my eyes. If a multiclass rogue/sorcerer with a penchant for darkness and illusion spells wanted to go into shadowdancer, though, why not? I think it's safe to say that they're not just trying to min/max their character at that point. Certainly you may want to work in a stronger in-game rationale before they reach some of the more unique shadowdancer abilities, but letting them jump start into the class isn't going to hurt anything; the first few class abilities mesh well enough with their character theme. Plus, doing things this way gives you some added flexibility when it comes to incorporating PrC organizations into the campaign. Suppose there do exist secretive orders of assassin/spies with powers of supernatural shadow--how do you think they're going to react when they hear that gee, there's this new adventurer guy hanging around, and gosh, some of his tricks look just like yours? There's loads of possibilities there, making it a lot easier to work this shadowdancer thing into the campaign in a more natural way, without having to interrupt other plot arcs or forcing the PC to put his advancement on the back burner.

[TheOOB]

When making a PrC, I make sure that it fits in one (or more) of the three following catagories.

1) Specializes the character in one aspect(eg. Dwarven Defender)
2) Gives the character abilities that are impossible to replicate using just base classes and feats/spells(eg. Arcane Archer)
3) Gives the character flavor by tieing them to an in-game group or organization(eg. Red Wizard)

I also firmly belive that a character should be forced to lose something in return for advancement in the class (which is often difficult, because most base classes are not designed to play well with PrCs).

Really, I find most of the best PrCs out there someone home brewed. People think of a character concept, then make a PrC to help them achieve that concept, and this in turn will help others make their characters with that class.

[Azerian Kelimon]

I'd have to agree with Alec. I usually institute some kind of "Special: X" requirement for getting into a PrC, sometimes even removing another requirement from it. Say, Archmage. To enter it, you must show your great dominion of magic by beating a previous archmage in contests of at least 3 different schools of magic (Example: You challenge an archmage to a contest of Conjuration, Enchantment, and Necromancy. For the first one, the most impressive abjuration wins, for the second one, both of you exchange Charm spells or something like that, and for the third, both of you try to summon the biggest undead you can). Or assasin. Maybe I don't have an assasin cabal in my world, so I change it: to enter, you must find a copy of a secret tome of poisons. It really makes a PrC earn the P part.

[Khanderas]

When making a PrC, I make sure that it fits in one (or more) of the three following catagories.

1) Specializes the character in one aspect(eg. Dwarven Defender)
2) Gives the character abilities that are impossible to replicate using just base classes and feats/spells(eg. Arcane Archer)
3) Gives the character flavor by tieing them to an in-game group or organization(eg. Red Wizard)

I also firmly belive that a character should be forced to lose something in return for advancement in the class (which is often difficult, because most base classes are not designed to play well with PrCs).

Really, I find most of the best PrCs out there someone home brewed. People think of a character concept, then make a PrC to help them achieve that concept, and this in turn will help others make their characters with that class.

I could not have put it better myself.