Here is a new class to act as a replacement for the Paladin, which I've removed from my setting as a core class to allow for more grey-areas in the morality.

Aside from the questionable wisdom of removing Paladins, what do you think of this class? Balanced? Broken?

HOLY KNIGHT
The warriors of the Church, Holy Knights are trained in the divine ways and martial expertise. Sworn to uphold the values and laws of their religion, Holy Knights belong to lawful or neutral religions. Though the common perception of the Holy Knights is of honour and duty and other ‘good’ abstractions, it is entirely possible for Holy Knights to be servants of totalitarian oppressive regimes (Lawful Evil) or harshly structured feudal systems (Lawful Neutral).

Adventures: Holy Knights take their adventures seriously and have a penchant for referring to them as "quests." Even a mundane mission is, in the heart of the Holy Knight, a personal test - an opportunity to demonstrate bravery, to develop martial skills, to learn tactics, and to find ways to serve their holy masters. Still, the Holy Knight really comes into her own when leading a mighty campaign against chaos, not when merely looting ruins.

Characteristics: Religious authority and training protects the Holy Knight and gives her special powers. At higher levels, the Knight can use selected spells [from the Holy Knight list] and turn away undead. In addition, this dedicated training and holy authority influences officials and other bastions of Law.

Alignment: Holy Knights must be Lawful, and they lose their divine powers if they deviate from that alignment. Additionally, Holy Knights swear to follow a code of conduct, described below.

Religion: Holy Knights must devote themselves to a single church, which must not be in any way chaotic. Devotion to righteousness is enough for most. Holy Knights are scrupulous in observing religious duties and are welcome in every associated temple.

Background: Holy Knights generally begin training as adolescents. Typically, they become squires or assistants to experienced Holy Knights, train for years, and finally set off on their own to further the causes of piety and law. Other Holy Knights, however, find their calling only later in life, after having pursued some other career. All Holy Knights, regardless of background, recognize in each other an eternal bond that transcends culture and race. Any two Holy Knights, even from opposite sides of the world, are likely to consider themselves equals and afford each other respect.

Races: Humans, with their ambitious souls, make great Holy Knights. Half-elves, who often have human ambition, may also find themselves called into service as Holy Knights. Dwarves are sometimes Holy Knights, but becoming a Holy Knight may be hard on a dwarf because it means putting the duties of the Holy Knights life before duties to family, clan, and king. Elven Holy Knights are few, and those few tend to follow quests that take them far and wide because their lawful bent puts them out of synch with life among the elves. Members of the other common races rarely hear the call to become Holy Knights. Among the savage humanoids, Holy Knights are all but unheard of.

Other Classes: Even though Holy Knights are in some ways set apart from others, they eagerly team up with those whose skills and capabilities complement their own. They work well with lawful clerics, and they appreciate working with those who are brave, honest, and committed to the Holy Knight’s church. Charismatic, well respected, and considered trustworthy, the Holy Knight makes a fine leader for a team.

GAME RULE INFORMATION
Holy Knights have the following game statistics.
Abilities: Charisma increases the Holy Knight’s healing and undead turning. Strength is important for a Holy Knight because of its role in combat. A Wisdom score of 14 or higher is required to get access to the most powerful Divine spells, and a score of 11 or higher is required to cast any Divine spells at all.
Alignment: Lawful (any).
Hit Die: d10.

Class Skills
The Holy Knight’s class skills (and the key ability for each skill) are;
Concentration (Con), Craft (Int), Diplomacy (Cha), Handle Animal (Cha), Heal (Wis), Knowledge (religion) (Int), Profession (Wis), and Ride (Dex).

Skill Points at 1st Level: (8 + Int modifier) x 4
Skill Points at Each Additional Level: 2 + INT modifier.



Class Features
All of the following are class features of the Holy Knight.

Weapon and Armour Proficiency: Holy Knights are proficient with all simple and martial weapons, with all types of armour (heavy, medium, and light), and with shields. Note that armour check penalties for armour heavier than leather apply to the skills Balance, Climb, Escape Artist, Hide, Jump, Move Silently, Pick Pocket, and Tumble. Also, Swim checks suffer a -1 penalty for every 5 pounds of armour and equipment carried.

Sanctuary: A Holy Knight may visit any castle of any territory practicing the same religion and request sanctuary. The castle owner must by this custom give the knight a place to stay for up to three days, along with food and drink. The host need not be friendly to the Knight, but may not attack, challenge of refuse sanctuary to the Knight. Similarly, the Knight may not attack or challenge the host or the members of the host’s court or family – doing so ends the sanctuary and the host is entitled to punish the Knight as fitting.

Bonus Feat: At 1st level and every three Holy Knight levels thereafter (4th, 7th, 10th, 13th, 16th and 19th), a Holy Knight can select a bonus feat from the Fighter's list.

Turn Undead: When a Holy Knight reaches 3rd level, she gains the supernatural ability to turn undead. She may use this ability a number of times per day equal to two plus her Charisma modifier. She turns undead as a cleric of one half her level would (rounding down). (See Turn and Rebuke Undead)
Extra Turning: As a feat, a Holy Knight may take Extra Turning. This feat allows the Holy Knight to turn undead four more times per day than normal. A Holy Knight can take this feat multiple times, gaining four extra daily turning attempts each time.

Spells: Beginning at 3rd level, a Holy Knight gains the ability to cast a small number of divine spells from their deity's Domain lists and the Holy Knight list. To cast a spell, the Holy Knight must have a Wisdom score of at least 10 + the spells level, so a Holy Knight with a Wisdom of 10 or lower cannot cast these spells. Holy Knight bonus spells are based on Wisdom, and saving throws against these spells have a Difficulty Class of 10 + spell level + Wisdom modifier. When the Holy Knight gets 0 spells of a given level, such as 0 1st-level spells at 4th level, the Holy Knight gets only bonus spells (as per Table 1-1: Ability Modifiers and Bonus Spells). A Holy Knight without a bonus spell for that level cannot yet cast a spell of that level.
A Holy Knight has access to any spell on the Holy Knight list and can freely choose which to prepare, just as a cleric can. A Holy Knight prepares and casts spells just as a cleric does (though the Holy Knight cannot use spontaneous casting to substitute a cure spell in place of a prepared spell). Through 1st and 2nd level, a Holy Knight has no caster level. Starting at 3rd level, a Holy Knight's caster level is one-half her class level.
Like Clerics, Holy Knights gain access to Domain spells granted by their deity, but do not gain them as bonus spells. They must prepare these spells as normal.

Holy Knight’s Code of Conduct: in addition to the requirement for a Lawful alignment, the Holy Knight must obey the following strictures.
Sworn Fealty to the Church: If summoned by the Church, the Holy Knight must report as quickly as possible and must serve as the Church orders. If the Knight ever refuses to obey the Church’s orders, or swears fealty to another religion (with the knowledge of any official of the Church), the Knight is Excommunicated (see below).
Service to the Church’s Lands: If a Call to Arms sounds, the Knight must respond. This declaration may only be issued by the leader of a large town or territory, or by the Church. The Knight need only respond if the issuing authority is one that practices the same religion as the Holy Knight. The ruler may order the Knight to fight in any way, but the Knight need not obey if the orders would go against the Code of Conduct or any edict from the Church.

Ex-Holy Knights
A Holy Knight who ceases to be lawful, or who grossly violates the code of conduct loses the Turn Undead ability and spells. She also may not progress in levels as a Holy Knight. She regains her abilities if she atones for her violations (see the atonement spell description), as appropriate.

Holy Knight Spell List
1ST-LEVEL HOLY KNIGHT SPELLS
Bless: Allies gain +1 on attack rolls and +1 on saves against fear.
Axiomatic Weapon: Weapon strikes true against chaotic foes.
Create Water: Creates 2 gallons/level of pure water.
Cure Light Wounds: Cures 1d8 damage +1/level (max +5).
Detect Poison: Detects poison in one creature or small object.
Detect Undead: Reveals undead within 60 ft.
Divine Favor: You gain +1 per three levels on attack and damage rolls.
Endure Elements: Exist comfortably in hot or cold environments.
Inflict Light Wounds: Touch attack deal 1d8 +1 per caster level (Max +10).
Magic Weapon: Weapon gains +1 bonus.
Protection from Chaos/Evil/Good: +2 to AC and saves, counter mind control, hedge out elementals and outsiders.
Read Magic: Read scrolls and spellbooks.
Resistance: Subject gains +1 on saving throws.
Virtue: Subject gains 1 temporary hp.

2ND-LEVEL HOLY KNIGHT SPELLS
Align Weapon: Weapon becomes good, evil, or lawful.
Bull’s Strength: Subject gains +4 to Str for 1 min./level.
Darkness: 20-foort radius of supernatural shadow.
Delay Poison: Stops poison from harming subject for 1 hour/level.
Eagle’s Splendor: Subject gains +4 to Cha for 1 min./level.
Hold Person: Paralyses 1 humanoid for 1 round/level.
Light: Object shines like a torch.
Owl’s Wisdom: Subject gains +4 to Wis for 1 min./level.
Remove Paralysis: Frees one or more creatures from paralysis or slow effect.
Resist Energy: Ignores 10 (or more) points of damage/attack from specified energy type.
Shield Other F: You take half of subject’s damage.
Undetectable Alignment: Conceals alignment for 24 hours.

3RD-LEVEL HOLY KNIGHT SPELLS
Cure Moderate Wounds: Cures 2d8 damage +1/level (max +10).
Daylight: 60-ft. radius of bright light.
Deeper Darkness: Object sheds supernatural shadow in a 60-foot radius.
Discern Lies: Reveals deliberate falsehoods.
Dispel Magic: Cancels spells and magical effects.
Inflict Moderate Wounds: Touch attack deal 2d8 +1/level (Max +10).
Magic Circle against Chaos: As protection from chaos, but 10-ft. radius and 10 min./level.
Magic Circle against Evil: As protection from evil, but 10-ft. radius and 10 min./level.
Magic Circle Against Good: As protection from good, but 10-foot radius and 10 min/level.
Magic Weapon, Greater: +1 bonus/four levels (max +5).
Prayer: Allies +1 bonus on most rolls, enemies –1 penalty.
Remove Curse: Frees object or person from curse.
Restoration, Lesser: Dispels magical ability penalty or repairs 1d4 ability damage.
Speak with Dead: Corpse answers one question/two levels

4TH-LEVEL HOLY KNIGHT SPELLS
Axiomatic Sword: Weapon becomes +5, deals +2d6 damage against chaos.
Break Enchantment: Frees subjects from enchantments, alterations, curses, and petrification.
Cure Serious Wounds: Cures 3d8 damage +1/level (max +15).
Death Ward: Grants immunity to death spells and negative energy effects.
Dispel Chaos: +4 bonus against attacks by chaotic creatures.
Dispel Evil: +4 bonus against attacks by evil creatures.
Dispel Good: +4 bonus against attacks by good creatures.
Mark of Justice: Designates action that will trigger curse on subject.
Neutralize Poison: Immunizes subject against poison, detoxifies venom in or on subject.
Restoration M: Restores level and ability score drains.
Zone of Truth: Subjects within range cannot lie.

Excommunication
(Aligned as per deity)

Level: Cleric 3
Components: V, S, DF
Casting Time: 10 minutes
Range: same plane
Effect: Excommunicates one divine character
Save: special
Spell resistance: no
Duration: Permanent
Excommunication is imposed by the target’s church in a ceremony performed by an ordained priest of that church. The target is symbolically and actually placed outside the protection of the patron god. An Excommunicated target is treated as having lost two levels of experience for the purposes of determining special divine class abilities. Spells are granted and cast as if two levels lower. Turning or Rebuking Undead functions at two levels lower. All other level dependent features, such as feats, skill points, hit points, saves etc, are unaffected. The target knows she has been Excommunicated. A target with a higher divine caster level than the caster is allowed a Will save to negate the effect. Thus a 12th level Paladin (caster level 6th) targeted by a 5th level Cleric of the same church is allowed a Will save, but if the same 5th level Cleric were to have the alignment domain of the patron deity (and thus cast this spell as if one level higher), the Paladin would not get to make a save.

Members of other religions, no matter how similar, may not be Excommunicated. The spell simply fails. The caster is not aware of the success or failure of the spell. The effects of this spell are removed by an Atonement spell only if the Atonement is cast by a member of the same religion of higher level than the caster of the Excommunication.

Divine Focus: An order signed by the ultimate ecclesiastical leader of the religion, or a specifically appointed agent thereof, without which, the ceremony has no effect. For example, a national sovereign ceremoniously called "Leader of the Faith" cannot provide such an order, it must come from the church's divine leader.


The intent of this spell is to hold some political fear over those characters in divine orders, and to provide an in-game reasoning for the punishment of aberrant Clerical behaviour.
As it can only be cast by clerics of the same religious order, I've levelled it at 3rd, despite it's horrible awesomeness. Is that still too low? I don't want to nerf the spell, I'd rather raise the level.

I think the level is ok when you consider the specific divine focus that the caster has to obtain to cast the spell successfully - there is potentially a whole gaming scenario behind that one, if a PC is trying to cast the spell!

Just one thing I spotted in the spell description:



This bit seems to have only been explained by being dropped in during the example - this factor perhaps needs further 'official' explanation beforehand, as it seems like quite an important part of the spell's rules?

It's a normal part of the rules, although I suppose it could do with more clarification.
Spells - particularly divine spells - often have an alignment. I mentioned at the start of the stat block for the spell that it is "aligned as per deity". This means that when the spell is cast by a priest of a LG god, the spell is Lawful and Good. If the caster has either the Law or Good domains, he casts spells of those alignments at +1 caster level.

but but but... you dont get a mount

Edited the OP to clarify abilities lost for breaching the Code of Conduct / alignment, and to allow for multi-classing. Holy Knights shouldn't be as restricted as Paladins, I reckon.

Could A holy night sound a call to arms if the cause was worthy enough?

No. He could ask the church leaders to do so, and if it is worthy enough as far as they see it, they'll do it for him - but it is not the place of the knight to make the call.

Silly question but I really want to know the answer; do Unholy Knights exist, if not could they?

No, and no.

You'll note that the Holy Knight is allowed to be evil, yes? They're just not allowed to be chaotic or neutral. Being a knight is about being part of a rule of law and honour and all that regimented stuff.
Without wanting to stray into real world politics or religious discussion, just think of all the terrible acts of rigidly doctrine-following evil that have been committed in the name of supposedly good faiths...
So there totally are EVIL holy knights. The "holy" in the name is a title, rather than a metagame description of their morality.

Ah, I see. Thanks for clearing that up for me.