(Some of the concepts I mention here are taken directly from the article I wrote in Dragon 274, "Create Your Own Prestige Class.")

A few weeks ago, I asked people on my message boards to submit some prestige classes so that we could "workshop" them and learn a few things about creating these classes, both good and bad. Thanks to the dozen or more participants who submitted their work -- and agreed to let me critique it in public!

Before I go too far, I will make just one point about prestige classes. A lot of the ones being designed and published today do not actually fill the role they originally were meant to fill. I get frustrated when I see people griping about prestige classes, when really what they are dissatisfied with is the way other people have interpreted prestige classes. The original design intention behind them was to allow DMs to create campaign-specific, exclusive roles and positions as classes. These special roles offer abilities and powers otherwise inaccessible to PCs and focus characters in specific, interesting directions.

The key there -- the one that's now often missing -- is that these are supposed to be DM-created tools, to lend specificity and actual mechanics to the details of your world. In short, you come up with some group, role, or whatever for your campaign (the Rangers of the Northwood, the Thief's Guild of Bandonburg, the Nightstalkers, etc.), and you create a prestige class based around that group. Too many prestige classes are designed like 2nd Edition kits: player-driven PC-creation tools for character customization. That's okay sometimes, but it really overlooks the main reason that prestige classes were invented. Oh well. That's my little rant.

So let's start at the beginning, with requirements:

All prestige class requirements are based around the idea that characters who qualifiy for the class are already well on their way to being able to do the things the prestige class excels in. Thus, if a feat seems appropriate to a prestige class, don't give it that feat as a benefit -- require that a character have that feat to take the class in the first place.

Two types of requirements can help you determine who can take a prestige class. The first type is game requirements. These are the feats, base attack bonus, skill ranks, etc. that a character must fulfill to qualify. The second type are roleplaying requirements. These are aspects of a character -- race, alignment, religion -- as well as deeds the character has accomplished. For example, everyone with the hunter of the dead prestige class, which specializes in fighting undead, must have had a negative level inflicted by an energy-draining undead. Sometimes these are simply roleplaying hooks that tie into the organization or culture a prestige class represents, like pledging allegiance to a monarch, paying initial membership dues, or performing a specific religious rite. While these really add life to a prestige class, don't use them for game balance purposes. They are just flavor.

When going over the prestige classes submitted on the message boards, I noticed two general things:

1. Base attack bonus is overused as a requirement. It's an easy yardstick to keep out characters that are still too low in level, but so are skill ranks (that's why you use skill ranks and not skill bonuses), base saving throw bonuses, spellcasting requirements, etc. Base saving throw bonuses are interesting, because using them encourages you to group character classes differently than you would if you'd chosen base attack bonuses. For instance, you can choose base Fortitude save bonus, which puts fighters, monks, and clerics on the same level, or choose base Will save bonus, and have clerics, wizards, and monks all meeting the requirements at the same time.

2. Too many seem focused toward one specific class. It's a shame, actually, that Wizards of the Coast decided to fill their class books with prestige classes, because they all were (obviously) geared toward encouraging a specific class to qualify for them. Prestige classes should be obtainable by more than one class. If you can make it so that multiple classes can qualify with the same ease and all get about the same benefits, you've really accomplished something.

Let's consider these requirements in Don Adam's Disciple of the Four Winds:

Jump: 10 Ranks
Balance: 10 ranks
Climb: 5 ranks
Alignment: Non-Chaotic
Feats: Dodge, Skill Focus (Jump), Run
Special: Leap of the Clouds
Unarmored Speed: 50 ft

Clearly, this one is for the monk. Now, look at those last two requirements. The Leap of the Clouds requirement already says "you must be a 7th-level monk," so there's no need for the speed requirement -- that says the same thing. (A 7th-level monk already moves that fast.) Unless the author meant to backhandedly restrict Small characters almost right out of the class (Small monks must be 15th level before they can get up to that speed), and that hardly seems appropriate -- there's nothing in the description that suggests a limit to "big folk" only -- this requirement is not necessary.

However, the other requirements are pretty good. The 10 ranks of Jump and Balance suggest a 7th-level character who's really focused on those skills. The feats are good, with the Skill Focus feat being practically a penalty. All of this suggests that the prestige class is going to offer some powerful abilities to match up with the fact that your first level in it will be your eighth character level, and you've really focused on one thing: movement and mobility.

Unfortunately, the class' abilities don't measure up to its harsh requirements. The base attack, Hit Dice, and saves are all as monk, except that Fortitude saves are worse. The special abilities are as follows:

1 Flying Leap
2 Nimble Northern Wind
3 Abundant Step 1/day, AC +1
4 Wavering Western Wind
5 Elevating Eastern Wind
6 Abundant Step 2/day
7 Silent Southern Wind
8 Slow Fall (any distance), AC +2
9 Improved Abundant Step
10 Four Winds Attack

Flying Leap (Su): A number of times per day equal to the Disciple's wisdom modifier multiplied by her class level, the Disciple may make a flying leap as a move equivalent action. The distance traveled is up to and including the Disciple's unarmored speed. In the case of a double move (which uses up two leaps), the Disciple's feet must touch the ground between the two leaps. The leap can be in any direction, but direction cannot be changed in midair.

Nimble Northern Wind: The monk gains the Psionic Charge feat as a virtual feat, usable at will despite any lack of psionic power points. It does not allow the selection of other psionic feats.

Abundant Step: This functions as the monk ability of the same name. At 6th level it is usable 2/day.
Wavering Western Wind: The Disciple learns how to harness her ki to temporarily improve her speed to unbelievable levels, making her incredibly difficult to see. In lieu of two stunning attacks for that day, the Disciple may act as if affected by a blur spell for a number of rounds equal to her Wisdom modifier. This may be enacted as a free action outside of the Disciple's turn, but only before an attack roll is made.

Elevating Eastern Wind: The Disciple gains the Up the Walls feat as a virtual feat, and can use it freely as with Psionic Charge. The Disciple can now, on a double move with two flying leaps, use a wall as the landing point between two leaps. This can only be done as the middle step of a double move. This does not allow the selection of other Psionic Feats.

Silent Southern Wind (Su): The Disciple can move up to 10 feet on a calm liquid with a successful Balance check vs DC 25. This ability allows the Disciple, with a successful Balance check, to use a calm liquid as the "mid-point" of a flying leap double move. The Disciple may also Move Silently at her full speed.

Slow Fall: This operates exactly the same as the monk ability of the same name.

Improved Abundant Step: The Disciple may now use the Abundant Step ability as a free action, and it can be used 3 times/day. It may only be used once per round.

Four Winds Attack: The Disciple can act as if hasted for 10 rounds per day. To invoke this ability is a free action, and it need not be used all at once.

Sure, this character can really move around the battlefield, but for monks to choose this, they give up ki strike, diamond body, quivering palm, et. al., plus -- and most importantly -- unarmed damage progression. This character is arguably worse than a monk, rather than a little better. Prestige classes should generally be as good as or a little better than a base class, because they have requirements; those with harsh requirements should be even a little better yet.

It's a good concept -- I love the visuals (I liked Crouching Tiger, Hidden Dragon, too), but unfortunately, a monk would be better off taking levels of wizard or sorcerer to get the blur, fly, and haste effects. I think this needs some work. Perhaps even a special bonus of +1 level of unarmed damage progression every level (or so), the way that spellcasters get +1 level of spells.

Now consider the internal alchemist, by Michael Tree. It has requirements (like the above monk) which are pretty harsh and mandate that the character be 7th level.

Alchemy: 10 ranks.
Concentration: 10 ranks.
Spellcraft: 8 ranks.
Heal: 5 ranks.
Feats: Brew Potion, Great Fortitude, Skill Focus (alchemy), and Toughness.
Spellcasting: Must be able to cast 3rd level arcane spells, including the spells alter self, endurance, endure elements, gentle repose, protection from elements, and resistance.

Most arcane spellcasters are going to take Concentration and Spellcraft anyway, but Heal (cross class) is uncommon, and Skill Focus (alchemy) is also a harsh "waste" of a feat. (As an observation, requiring specific spells -- particularly spells like gentle repose -- suggests that this will probably be a wizard, not a sorcerer.) In return, however, the internal alchemists gain their normal spell progression every level plus other stuff.

The other stuff isn't really all that unbalancing, however -- most are not new abilities, but ways to do things the character can already do, but better. For a class getting all of its original spellcasting progression, that's a really good way to go.

Enchanted Flesh: An internal alchemist has the ability to alchemically store magical effects within his own body. Essentially the internal alchemist uses the Brew Potion feat as normal, but stores the potion within himself. He can activate the potion through concentration as a standard action that draws an attack of opportunity, like casting a spell, and can channel the effect into another target by touch if desired. The maximum number of enchantments the internal alchemist canstore at one time is equal to his levels of internal alchemist plus his Constitution score, but if he is ever slain, they are all immediately ruined, even if he is subsequently returned to life.

Internal Medicine: At 2nd level the internal alchemist gains such precise alchemical control over his body that he can purge himself of diseases, including magical diseases such as mummy rot and lycanthropy. Whenever the internal alchemist is at risk of being infected by a disease, he can make a Heal check as a free action in place of a saving throw, and use that result for his save. If this Heal check is successful, the internal alchemist purges himself of the disease and need not make any further saves against it. If the disease does not normally allow a saving throw, the internal alchemist may still make a Heal check to resist it (DC 10 + 1/2 the inflicting creature's HD + the creature's Constitution modifier).

At 4th level, the internal alchemist gains the same abilities with regards to poison.

At 6th level, the internal alchemist can even use his internal medicine to resist or undo the effects of necromantic and transmutation spells and spell-like abilities upon his body. To do so, he must make a Heal check (as above) against a DC of 11 + the caster level of the effect.

If the internal alchemist does not or cannot use this ability when he first encounters a disease, poison, or appropriate magical effect, and he becomes affected by it, he may later make a Heal check (as above) to purge himself of it, as per the spells remove disease, neutralize poison, and break enchantment, respectively.

Magical Artisan: At 3rd level, the internal alchemist gains increased mastery of the art of brewing potions. When determining the cost in XP and raw materials of potions that the internal alchemist brews, including the use of his enchanted flesh ability, multiply the base price by 75%.

Internal Alchemy: At 5th level, the internal alchemist develops such precise control over his body and bodily forces that he gains the ability to cast personal-range spells and other spells which affect only him without somatic, verbal, or common material components, as a full-round action. To do so, the internal alchemist must make an Alchemy check with a DC of 20 + the level of the spell he's casting. If he fails this check he loses the spell. If the material components cost more than 1 gp, he requires them to cast the spell as normal.

As an observation, we already know that the character's got at least 10 ranks in alchemy, and Skill Focus (alchemy), so this DC is not too hard. Considering this, for example, gets around the costly component of stoneskin and gives the character the feats Still Spell and Silent Spell (for spells he casts on himself), internal alchemy is perhaps the best ability this character gets. This guy could put on plate armor and cast truestrike, blur, invisibility, haste, displacement, and all sorts of other good spells without risking spell failure.

Extended Alchemy: At 7th level, the internal alchemist can brew potions that have extended durations, as if under the effects of a Extend Spell feat, without altering the level of the spell. He may also use this ability with his Enchanted Flesh and Internal Alchemy abilities, though with the latter extending a spell adds +5 to the DC of the Alchemy check required to cast it.

Guarded Life: Starting at 8th level, the internal alchemist is allowed a saving throw against energy drain, death attacks, inflicted negative levels, and ability damage or loss, even if no save is normally allowed. Spell DCs are calculated normally, while other saves have a DC of 10 + 1/2 the inflicting creature's HD + the creature's Constitution modifier (or Charisma modifier if undead).

Potion Potency: Upon reaching 9th level, the potions the internal alchemist brews are especially potent. The save DCs of all potions that he creates are increased by 2, including those stored with his enchanted flesh ability.

Save DCs? For potions? This power isn't very good. There are three potions in the DMG that involve saves (fire breath, love, and truth). On the other hand, you're probably willing to accept this as your 9th-level ability just to get to the 10th-level ability.

Alchemical Immortality: On reaching 10th level, the internal alchemist achieves his ultimate goal and becomes effectively immortal. He no longer suffers ability penalties for aging, cannot be magically aged, and will never die of old age. Any penalties he may have already suffered, however, remain in place, and bonuses still accrue. In addition, he may use Internal Medicine even when unconscious or incapacitated, he becomes immune to death from massive damage, and if he is reduced to 0 or less hit points he stabilizes automatically and heals 1 hit point per round until he has positive 1 hit point. If the alchemical immortal is reduced to -10 hit points he dies, as normal.

The last part, about stabilizing automatically and fast healing, is probably too good. It's worth playtesting, but with this guy being so resistant to death attacks, poison, and disease, becoming immune to death from massive damage might just make him too hard to kill.

When balancing prestige class abilities, the number one way to look at it is to ask yourself: If a character didn't take this class, where would he be and what could he do? Then compare your answer to the things your prestige class can do. I like the internal alchemist a lot, but coupled with his normal spell progression, a couple of his abilities make him so much better than a normal wizard or sorcerer, the class is probably not properly balanced. I think I'd consider taking the internal alchemy ability and applying it to a higher level (perhaps ditching the 9th-level ability altogether), and toning down the 10th-level ability.

A couple of final words about prestige class abilities:

The first ability or abilities gained from a prestige class should match the minimum level that a character could possibly be to qualify for the class. Thus, if a ranger can qualify for the class at 4th level, the first level of the prestige class should be approximately equivalent to the fifth level a ranger might gain.

Much of the trick of balancing prestige class levels lies in the small issues: Base attack increases, Hit Die size, and even weapon and armor proficiency can be strong enticements to take a level in the prestige class. Remember that gaining proficiency in weapons or armor is like gaining free feats.

Take a look at the other classes presented in the message boards, and let's continue this discussion there. Also, while you're on the boards, let me know if you'd like to see more online design workshops like this one.