Oaths for Divine Casters

    Most OSR games, in particular retro-clones, have a tendency to limit clerics and other divine casters from acquiring high-level spells. This is usually because they're based on either AD&D, in which divine spells only went to level 7, or B/X, in which all spellcasters are capped off at 6th level spells. I thought it would be interesting to come up with a way to allow divine casters to gain spells beyond that limit through interactions with the campaign world.

    I think the best way for divine spellcasters specifically would be for them to make some kind of deal with their diety. Similar to magic-users patrons in games like DCC, the cleric could call upon whichever god they serve and take on an oath in exchange for more extraordinary powers. These oaths could be anything from an oath of poverty to a promise to complete a divine quest. Should the cleric break this oath they should at the very least lose access to their higher level spellcasting and may incur other punishments from their diety. This can lead to interesting campaign hooks while also giving your high-level clerics a more direct relationship with their diety.

    The exact powers the cleric receives are determined by the referee. It is probably easiest to give them a single spell slot per oath and use a spell list from a version of the game with higher-level divine casters. But it could also be interesting to make their new spells into class abilities like turn undead or have the PC make oaths for knowledge of spells rather than for spell slots. Either way, the reward for an oath should generally be an equal reward to the severity of the oath. A character who swears to never lie to a non-chaotic creature should not receive the same reward as a character who swears an oath of eternal silence. The cleric and god should negotiate as to what the cleric receives in exchange for their oath, but keep in mind that the diety holds all the cards.

    Though this is mainly meant for clerics, oaths could also be interesting for paladins and druids. Paladins' high combat ability is balanced by their fairly limited spellcasting, so allowing them to make an oath for more power could lead to an immensely powerful character. Because of this, their oaths should be especially restrictive. Druids typically aren't depicted as having patron deities, but they might make deals with animistic spirits or some sort of fey council. the oaths of druids and paladins should be different in nature from those of clerics, and clerics should have different oaths depending on what sort of god they worship. A god of torture will require different oaths from their followers than a god of kindness.

    Oaths can also be used in other situations. A non-divine caster may take one up out of religious devotion, or in exchange for some sort of divine intervention. An enforced oath of poverty or silence might also make a good punishment for a misbehaving cleric. A fighter might take on an oath in exchange for a magic weapon, losing that weapon if they break their vow. There are plenty of potentially entertaining ways to build off oaths as a concept.

    The following is a d12 table of potential oaths. They are of varying severity in order to show how wide a gap there can be in the limitations of an oath. One can imagine a god of fishermen giving their cleric a 7th level spell after they take on an oath of poverty, or a god of chaos granting their servant level 9 spells so that they can fulfill their crusade oath, leading an army to destroy all lawful settlements they encounter. I tried to keep the descriptions fairly vague so that the referee can determine the specifics of the oath.

#	Oath	Description
1	Poverty	Oathtaker must give up a percentage of their income to a church or charity
2	Abstinence	Oathtaker must abstain from a worldly pleasure of the referees choice
3	Penance	Oathtaker must work to undo whatever the referee deems to be their greatest character flaw
4	Combat	Oathtaker must immediately enter combat with any enemies of their deity that they encounter
5	Simplicity	Oathtaker must cast aside any fine goods they may own or use
6	Sincerity	Oathtaker may not intentionally tell a lie to a character of the same alignment
7	Honesty	Oathtaker may never lie
8	Favored Weapon	Oathtaker may only use the favored weapon of their diety
9	Quest	Oathtaker must complete a mission of the deity's choice before receiving their new ability
10	Silence	Oathtaker must never speak
11	Crusade	Oathtaker must undertake an ongoing campaign against the enemies of their deity
12	Charity	Oathtaker must form and lead an organization for the betterment of society at large

Switching Classes

Intro

    A player switching the class of a long-running character can make for an interesting moment in your campaign. Why would the character suddenly change their entire skillset? For the player, it is usually because they got bored of playing their old class, or they're creating a complex build. In-game, it can create an interesting narrative moment. It can be interesting to consider what would motivate a character to make such a drastic change, and mechanically it can lead to some interesting subsystems.

    The typical way for a character to gain a new class in OSR games is through dual classing. This system works fine when switching between very different classes, like a thief to a magic-user, or a magic-user to a cleric, but it's a bit awkward when switching between classes of the same type, largely because it starts the character over at first level. A fighter who dual classes to become a paladin or ranger will have to relearn the same fighting skills they already know from being a baseline fighter. This always seemed a bit awkward to me, especially regarding paladins. 

    Paladins become fighters when they break their oaths and regain them if they perform some sort of redemptive quest for their diety. This means that the only real difference between a fighter and a paladin is the approval of their god. So shouldn't a fighter who fits the requirements be able to become a paladin of equivalent power by completing a similar redemptive quest? I think that there should be a system of switching between classes of the same archetype for this sort of situation. The following is my attempt to write one.

Class Switching Rules

    All old school D&D classes fit vaguely into one of four archetypes relating to the core classes, often referred to as warriors, priests, mages, and rogues. Members of these archetypes are variants of fighters, clerics, magic-users, and thieves respectively. As an example, here are the classes from Advanced Fantasy OSE split into the different class archetypes:

Warrior: Barbarian, Fighter, Knight, Paladin, Ranger

Priest: Cleric, Druid, Bard

Mage: Illusionist, Magic-User

Rogue: Acrobat, Assassin, Thief

    Within this system of swapping classes, each PC is able to switch between classes of the same archetype as long as they perform some sort of task; the exact details of which vary depending on the class. A fighter becoming a paladin might need to prove themselves with a holy quest, while a thief hoping to become an acrobat would have to find a master to teach them. The character does not maintain their previous level but does have the same amount of experience. That means a newly minted paladin may be a lower level than they were as a fighter. Should race-as-class be used, demi-humans are not able to switch between classes.

    Some classes do not quite fit into the typical class types. Monks for example primarily function as warriors, are priests within the game world, and usually have thieves skills like a rogue. In those cases, I would allow the player to switch classes to the core class of any of those types, fighter, cleric, or thief, but none of the subclasses like ranger, druid, or assassin. The referee may also consider them too different from any other class for the skills to transfer over and use dual classing instead.

    This rule of class switching would work well for players who have grown bored with their original class but don't want to retire their character. Many first-time players start as fighters or thieves while learning the rules of the game, but want something more complex once they have gotten used to the system. Class switching would allow them to branch out while staying in their comfort zone and not having to start over from the beginning. It can also be used in dramatic points in your campaign. A fighter may perform a heroic task for a diety and receive paladin powers as a response, or train with a master hunter and become a ranger. Such things can easily lead to interesting campaigns.

Conclusion

   This is just a general house rule. I tried to format it in a way that makes sense. I think I mostly succeeded in this, though I fear it rambles on a bit. I was inspired a bit by how BECMI deals with paladins and druids, by allowing 9th level characters to choose them as subclasses. I like the BECMI system a lot, though I get that a lot of players like being able to start as their preferred class. Feel free to leave your thoughts in the comments, I'd be happy to read them.