Unforntunately, no... The Wizard's ritual spellcasting ability specifically states that it must be both a Wizard spell and a spell transcribed into your Wizard Spellbook.
A Cleric 1/Other Class X has access to the Cleric spells of a level 1 Cleric: that would be all 1st level spells on the Cleric Spell List, as well as any other spells treated as Cleric Spells by your subclass. Those first level spells are all that you can "prepare" as a Cleric, even if you know other spells from other classes, feats, or racial features. Augury is a second-level spell, so no you don't have the ability to prepare it as one of your Cleric spells.
The Cleric's ritual casting feature provides:
Ritual Casting
You can cast a cleric spell as a ritual if that spell has the ritual tag and you have the spell prepared.
I could go off on a tangent about how a cleric spell is any spell on the cleric list, not a spell you have access to by virtue of being a cleric... but it's an argument not worth having here, because either way, it must be a "prepared" spell not just a known spell, and the other preparation caster classes (druid, wizard, and artificer) all also have Ritual Casting. So there's no edgecase where you'd even want to prepare say a Cleric/Druid spell as a druid, but ritual cast it using the Cleric ritual casting feature, it's just not realistic.
Anway, sorry, off topic.... the new UA Class Feature variants has actually added Augury to the Wizard spell list, so if using that option your Cleric 1/Wizard 3 would have access to that spell and could copy it into their spellbook. Doing so isn't really a waste, even though they'll eventually get it with only two more levels more of Cleric, because the Wizard ritual casting feature is quite a bit better than Cleric's: no need to choose the ritual spell as one of your limited prepared spells per day!
Ritual Casting
You can cast a wizard spell as a ritual if that spell has the ritual tag and you have the spell in your spellbook. You don’t need to have the spell prepared.
You can cast a cleric spell as a ritual if that spell has the ritual tag and you have the spell prepared.
I could go off on a tangent about how a cleric spell is any spell on the cleric list, not a spell you have access to by virtue of being a cleric... but it's an argument not worth having here, because either way, it must be a "prepared" spell not just a known spell, and the other preparation caster classes (druid, wizard, and artificer) all also have Ritual Casting. So there's no edgecase where you'd even want to prepare say a Cleric/Druid spell as a druid, but ritual cast it using the Cleric ritual casting feature, it's just not realistic.
...
Yes, the book distinguishes between two different lists of spells for each class, the class spell list (which is printed in the rulebooks with additions in the rules expansions) and the list that is generally more important to each character: the list of spells that that character knows as a particular class. That is pretty clear reading the text of the spellcasting feature of each class and doubly so when you read the multiclassing rules that clearly state "each spell you know and prepare is associated with one of your classes, and you use the spellcasting ability of that class when you cast the spell." It can't be more obvious, it is in plain as day english.
Luckily for ritual spells, all that doesn't really matter since the requirements are different: the only requirements for any character with any levels of cleric to cast a spell as a ritual are being a cleric spell and being prepared -- this is when the class spell list matters since the wording doesn't mention "your cleric spells" or anything else of the like. Also luckily for ritual spells, none rely on your spellcasting modifier, so it doesn't really matter if you ritually cast detect magic or gentle repose as a wizard or a cleric.
If you want even more cleric rituals than first level and the few that overlap, you can either sacrifice levels to cleric or an ASI to ritual caster (cleric).
This is a very interesting question, and I'm not certain if the answer is clear.
Clerics can ritual cast any spell they have prepared, so what is required for a cleric to prepare a spell? The number of spells a cleric can prepare is bound by class level, but the level of the spell is not bound by class level. It is determined by the level of spell slots available.
"You prepare the list of cleric spells that are available for you to cast, choosing from the cleric spell list. When you do so, choose a number of cleric spells equal to your Wisdom modifier + your cleric level (minimum of one spell). The spells must be of a level for which you have spell slots."
A multiclass cleric/wizard likely has higher level spell slots available. A cleric is unique because they don't learn spells, all cleric spells are available for a cleric to prepare if they meet the requirements for preparing the spell. The only limit given in the cleric class rules is that they have the right level of spell slot. So do the multiclass rules place any other limits? There are two relevant rules.
"Spells Known and Prepared. You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class."
This rule doesn't specifically say anything about spell slots. I think that there is room for interpretation either way, but a strict reading doesn't limit the cleric from preparing higher level spells.
"Spell Slots. You determine your available spell slots by adding together all your levels in the bard, cleric, druid, sorcerer, and wizard classes, half your levels (rounded down) in the paladin and ranger classes, and a third of your fighter or rogue levels (rounded down) if you have the Eldritch Knight or the Arcane Trickster feature. Use this total to determine your spell slots by consulting the Multiclass Spellcaster table.
If you have more than one spellcasting class, this table might give you spell slots of a level that is higher than the spells you know or can prepare. You can use those slots, but only to cast your lower-level spells. If a lower-level spell that you cast, like burning hands, has an enhanced effect when cast using a higher-level slot, you can use the enhanced effect, even though you don't have any spells of that higher level."
The relevant distinction made in this rule is the reference to the "Multiclass Spellcaster table." How distinct is this table from the "Cleric table" and the "Wizard table"? (Arguably, a single class character is eligible to use the "Multiclass Spellcaster table.")
The paragraph on cleric casting mentions the "Cleric table", but the paragraph on preparing does not. (The section for wizards to write a spell in their spellbook directly references the "Wizard table.")
A very strict reading does not limit a cleric from preparing spells of any level for which they have slots. If they can prepare the spell then they can ritually cast it.
More generally, should the rules be interpreted to allow clerics to prepare spells of a higher level than a spontaneous caster could? The rules aren't 100% clear.
When the DM has to make a call on an unclear rule, I would argue that the rule of fun needs to be taken into account. On the one hand, would it make the character too powerful and take away the fun for the rest of the party? Or if the character is going to use these higher level cleric spells to cast utility rituals that help the entire party, why not allow it?
I'm sorry, but you quoted the relevant text example in your rules quote.
You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class."
This is clear. You prepare spells as though you were a single caster at a time: a cleric 1 can prepare level 1 cleric spells. A wizard 3 can prepare 1st and 2nd level wizard spells. There are even examples to help you.
If you have more than one spellcasting class, this table might give you spell slots of a level that is higher than the spells you know or can prepare.
This sentence only can exist if there is the possibility of having slots of levels for which you cannot know spells. The only way that can happen is if you read the first quoted sentence in the obvious (and strict and RAW) way. If one prepares spells as you suggest this sentence has no meaning.
Edit 2: Finally, making the leap that any character can use the MC spellcasting table to determine their spell slots available "as a single classed member" is a huge assumption with no mechanical support and therefore requires anything BUT a strict reading (unless you are saying that a cleric 1 uses row 1 from that table). "It doesn't say we can't" is never a good basis for a "strict" reading of RAW.
This is a very interesting question, and I'm not certain if the answer is clear.
"Spells Known and Prepared. You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class."
This rule doesn't specifically say anything about spell slots. I think that there is room for interpretation either way, but a strict reading doesn't limit the cleric from preparing higher level spells.
When the DM has to make a call on an unclear rule, I would argue that the rule of fun needs to be taken into account. On the one hand, would it make the character too powerful and take away the fun for the rest of the party? Or if the character is going to use these higher level cleric spells to cast utility rituals that help the entire party, why not allow it?
A single class character does not use the multiclass spell slot table, because a single classed character is not multiclassed. I hope that wasn't too complicated, but that concept is important for balancing multiclassing.
If the rule of fun were to supersede this RAW concept, it would allow a wizard 18/cleric 1/druid 1 to have access to the same spells as a level 20 Wizard, level 20 cleric, and level 20 druid and be able to prepare and cast essentially any spell in the game. A single level of mutliclassing should not gain 17+ levels of features from that 1 level.
World, the argument is... the single-classed rule for a Cleric (and also the other preparation casters) is "prepare anything you have a spell slot for", not anything resembling the known-spell casters which reads "the Spells Known column of the [Class X] table shows when you learn more [class x] spells of your choice." Contrast:
You prepare the list of cleric spells that are available for you to cast, choosing from the cleric spell list. When you do so, choose a number of cleric spells equal to your Wisdom modifier + your cleric level (minimum of one spell). The spells must be of a level for which you have spell slots.
versus
The Spells Known column of the Sorcerer table shows when you learn more sorcerer spells of your choice. Each of these spells must be of a level for which you have spell slots. For instance, when you reach 3rd level in this class, you can learn one new spell of 1st or 2nd level.
If you read a known-spell caster's spellcasting feature "as a single-classed member of that class," it's clear that you know spells based on the numbers that show up in the class table, no matter what your spell slots look like for whatever reason. But when you read a preparation caster's spellcasting feature "as a single-classed member of that class," it tells you to look only at your spell slots. The multi-class spellcaster rules, which tell you to read your cleric spellcasting feature as if you're a single class cleric, don't actually stop you from preparing spells based on all of the spell slots you have available.
I'm in the camp that this is RAW despite being very very clearly not RAI (why would non-prep casters be punished in a way that prep casters aren't?) and I think you're not likely to win many points at a table trying to argue for it with your DM, but unless we get an errata which closes that loophole, Snake has a point.
Why did you highlight two different sentences in the quotes when both have sentences that say "... of a level for which you have spell slots"? That is the definition of cherry-picking.
World, the argument is... the single-classed rule for a Cleric (and also the other preparation casters) is "prepare anything you have a spell slot for", not anything resembling the known-spell casters which reads "the Spells Known column of the [Class X] table shows when you learn more [class x] spells of your choice." Contrast:
You prepare the list of cleric spells that are available for you to cast, choosing from the cleric spell list. When you do so, choose a number of cleric spells equal to your Wisdom modifier + your cleric level (minimum of one spell). The spells must be of a level for which you have spell slots.
versus
The Spells Known column of the Sorcerer table shows when you learn more sorcerer spells of your choice. Each of these spells must be of a level for which you have spell slots. For instance, when you reach 3rd level in this class, you can learn one new spell of 1st or 2nd level.
You bolded completely different parts of these rules. For sorcerer you bolded the sentence that says how many spell they know and when they learn them. Clerics also have rules for how many spells they can prepare (which you quoted but didn't bold) and when they can prepare them (which you did not include in your quote).
The whole sentence you quoted from cleric (since the partial bolded sentence seems irrelevant to your point) states what level spells a cleric can prepare. Sorcerers have a nearly identical sentence which you quoted but didn't bold.
Whatever claim you are trying to make about prepare casters would have to apply to both prepare casters and learn casters.
Luckily, it doesn't matter and your self contradicting claims are irrelevant because the RAW is clear.
Spells Known and Prepared. You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class.
So if you are single class the only thing you have to go on for what slot you have are:
Preparing and Casting Spells
The Cleric table shows how many spell slots you have to cast your cleric spells of 1st level and higher.
Spell Slots
The Sorcerer table shows how many spell slots you have to cast your sorcerer spells of 1st level and higher.
I quoted different parts because they are laid out differently, not out of any attempt to obfuscate. The answer to what spells a known-caster can cast is “the spells that they know.” For a prepared caster, it’s “the spells that they prepare.” That’s why those are the sections I contrasted: a sorcerer knows the spells that their table allows them; while a cleric prepares spells based on their slots.
I quoted different parts because they are laid out differently, not out of any attempt to obfuscate. The answer to what spells a known-caster can cast is “the spells that they know.” For a prepared caster, it’s “the spells that they prepare.” That’s why those are the sections I contrasted: a sorcerer knows the spells that their table allows them; while a cleric prepares spells based on their slots.
But the sorcerer table allows them to learn spells of a level of which they have slots. It uses almost identical wording to clerics. The only difference is the timing that they choose spells, not the limitations on the spells they can choose.
I think it's a bit unfair to imply that the phrase "as if you were a single-classed member of that class" requires no interpretation. A first question might be: single class, but at what level? The rule alone doesn't answer this question, but the example does. There is need for a lot of interpretation on this rule, even if that interpretation feels like it is obvious. I don't think that it is unreasonable to show the rule to a DM and tell them that you want to ritual cast higher level spells.
Imagine a related but different case. It is entirely up to the DM whether or not a wizard can use another wizard's spell book. There is no RAW on this question either way. It is a common thing that happens in fiction, probably even in the forgotten realms books, and is a very fair question to ask of a DM. A wizard could use the spell book to cast higher level rituals than they would otherwise be allowed to, because wizards don't have the restriction that the ritual has to be prepared. I could imagine a lot of DMs allowing this.
You can cast a wizard spell as a ritual if that spell has the ritual tag and you have the spell in your spellbook. You don't need to have the spell prepared."
That's from the wizard features, that being said you can still ritual cleric spells but you have to prepare them, further more the way cleric work is THEY KNOW ALL OF THERE SPELLS so if you have ONE level in cleric so long as you have a spell slot of the correct level you can prepare any of there spells, of you are a level 5 wizard and a level 1 cleric you can prepare up to 6 cleric spells (if you have 20 wisdom)
With all that information here is the answer your question: you can use any ritual cleric cleric spell so long as you have ot prepared and you have a appropriate spell slot to cast it with (even though a ritual cast doesn't consume a spell slot, you need access to spell slots of that level in order to prepare and cast it). Wizard rituals spells you can cast without having it prepared because WoTC really likes wizards
Imagine a related but different case. It is entirely up to the DM whether or not a wizard can use another wizard's spell book. There is no RAW on this question either way. It is a common thing that happens in fiction, probably even in the forgotten realms books, and is a very fair question to ask of a DM. A wizard could use the spell book to cast higher level rituals than they would otherwise be allowed to, because wizards don't have the restriction that the ritual has to be prepared. I could imagine a lot of DMs allowing this.
Actually there is a RAW answer to this question:
Copying a Spell into the Book. When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a spell level you can prepare and if you can spare the time to decipher and copy it.
Copying that spell into your spellbook involves reproducing the basic form of the spell, then deciphering the unique system of notation used by the wizard who wrote it. You must practice the spell until you understand the sounds or gestures required, then transcribe it into your spellbook using your own notation.
Simply put: you can only cast the spells in your spellbook, and can't even copy spells into it that are higher than you can cast.
When you multiclass from another class into wizard, you suddenly get handed a spellbook that contains six first level spells. This isn't necessarily a spellbook you wrote by hand, you certainly don't have to pay the gold cost to transcribe those spells, it's just a class feature you suddenly have. Some DMs might not like that and impose additional downtime hoops to justify the sudden appearance of this book, but a lot will be okay with saying "you found another wizard's spellbook." That isn't cutting corners, RAW there's no special cost or requirement for that book to spring into being, and JC has suggested that it's RAI as well. Snake isn't out on a limb that in a game where the DM has made that ruling once when you first multiclass into wizard, a player would have a good argument if they later find another higher level spellbook to tell the DM "this is my spellbook now, I'm trading up." If a wizard is able to embrace a book penned by someone else as "their spellbook" at level 1, it's hard to see what's stopping them from doing that later as well, if they're willing to leave their former book behind.
I think it's a bit unfair to imply that the phrase "as if you were a single-classed member of that class" requires no interpretation. A first question might be: single class, but at what level? The rule alone doesn't answer this question, but the example does. There is need for a lot of interpretation on this rule, even if that interpretation feels like it is obvious. I don't think that it is unreasonable to show the rule to a DM and tell them that you want to ritual cast higher level spells.
Imagine a related but different case. It is entirely up to the DM whether or not a wizard can use another wizard's spell book. There is no RAW on this question either way. It is a common thing that happens in fiction, probably even in the forgotten realms books, and is a very fair question to ask of a DM. A wizard could use the spell book to cast higher level rituals than they would otherwise be allowed to, because wizards don't have the restriction that the ritual has to be prepared. I could imagine a lot of DMs allowing this.
It is extremely unreasonable to show the DM a rule but hide from him the next sentence that shows you how the game wants that rule to work. Maybe the writers of the book were self-aware enough to know that without an example, some people simply could not interpret the phrase "single-class member of that class." Who knows why its there, but any example in the rules text is there to clarify and show you how the rules work. The rules are to work the way the example works.
Your other example is unrelated, but I will address it. What you are describing has more to do with RP than mechanics. RAW again and again refer to your spellbook, but never describe how you got it. It only explains how you choose spells from your spellbook to cast and how you add to your spellbook. As long as you follow those rules, other things are just RP. You could in theory have a library of spellbooks from dead wizards if you wanted to RP that way, but you still need to follow the rules for how you add spells (6 + 2 more for each wizard level + gold and time for more) to your collection and how you select which to prepare (wizard level + int). In 5e you cannot just pick up a spellbook and cast any spell in it. You could, up to DM discretion, be allowed to say your spellbook is a collection of spellbooks that you didn't actually write - but I have no idea how you'd RP the 50 gp and 2 hrs of time for copying spells into it if you are saying you found it.
So, to add another fun layer... what if for Level 1 I chose the Cleric Domain of Knowledge... Thus granting Identify and Augury as Known/Always Prepared Spells?
RAF and RAI, once you know those spells at the appropriate levels, I think that you can cast them at rituals.
RAW, you have to decide if the “a cleric spell with the ritual tag” means literally what it says or “a cleric spell for you” as the rules for casting with slots says. As I have mentioned, the rules indicate that there are two lists important to casters: the list of spells that they choose what they know or prepare from — the class list — and the list of spells that they can cast as a particular class. Unlike with casting using slots, this text doesn’t use words like “for you” or “cleric spell list.”
Sorry if this has been answered, I haven't found it if it has.
I have a Cleric 1, Wizard 3 (Divination) character. I'd really love to be able to cast Augury as a Ritual but I'm not sure if that is possible??
Unforntunately, no... The Wizard's ritual spellcasting ability specifically states that it must be both a Wizard spell and a spell transcribed into your Wizard Spellbook.
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A Cleric 1/Other Class X has access to the Cleric spells of a level 1 Cleric: that would be all 1st level spells on the Cleric Spell List, as well as any other spells treated as Cleric Spells by your subclass. Those first level spells are all that you can "prepare" as a Cleric, even if you know other spells from other classes, feats, or racial features. Augury is a second-level spell, so no you don't have the ability to prepare it as one of your Cleric spells.
The Cleric's ritual casting feature provides:
I could go off on a tangent about how a cleric spell is any spell on the cleric list, not a spell you have access to by virtue of being a cleric... but it's an argument not worth having here, because either way, it must be a "prepared" spell not just a known spell, and the other preparation caster classes (druid, wizard, and artificer) all also have Ritual Casting. So there's no edgecase where you'd even want to prepare say a Cleric/Druid spell as a druid, but ritual cast it using the Cleric ritual casting feature, it's just not realistic.
Anway, sorry, off topic.... the new UA Class Feature variants has actually added Augury to the Wizard spell list, so if using that option your Cleric 1/Wizard 3 would have access to that spell and could copy it into their spellbook. Doing so isn't really a waste, even though they'll eventually get it with only two more levels more of Cleric, because the Wizard ritual casting feature is quite a bit better than Cleric's: no need to choose the ritual spell as one of your limited prepared spells per day!
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I'm going to make this way harder than it needs to be.
Yes, the book distinguishes between two different lists of spells for each class, the class spell list (which is printed in the rulebooks with additions in the rules expansions) and the list that is generally more important to each character: the list of spells that that character knows as a particular class. That is pretty clear reading the text of the spellcasting feature of each class and doubly so when you read the multiclassing rules that clearly state "each spell you know and prepare is associated with one of your classes, and you use the spellcasting ability of that class when you cast the spell." It can't be more obvious, it is in plain as day english.
Luckily for ritual spells, all that doesn't really matter since the requirements are different: the only requirements for any character with any levels of cleric to cast a spell as a ritual are being a cleric spell and being prepared -- this is when the class spell list matters since the wording doesn't mention "your cleric spells" or anything else of the like. Also luckily for ritual spells, none rely on your spellcasting modifier, so it doesn't really matter if you ritually cast detect magic or gentle repose as a wizard or a cleric.
If you want even more cleric rituals than first level and the few that overlap, you can either sacrifice levels to cleric or an ASI to ritual caster (cleric).
This is a very interesting question, and I'm not certain if the answer is clear.
Clerics can ritual cast any spell they have prepared, so what is required for a cleric to prepare a spell? The number of spells a cleric can prepare is bound by class level, but the level of the spell is not bound by class level. It is determined by the level of spell slots available.
"You prepare the list of cleric spells that are available for you to cast, choosing from the cleric spell list. When you do so, choose a number of cleric spells equal to your Wisdom modifier + your cleric level (minimum of one spell). The spells must be of a level for which you have spell slots."
A multiclass cleric/wizard likely has higher level spell slots available. A cleric is unique because they don't learn spells, all cleric spells are available for a cleric to prepare if they meet the requirements for preparing the spell. The only limit given in the cleric class rules is that they have the right level of spell slot. So do the multiclass rules place any other limits? There are two relevant rules.
"Spells Known and Prepared. You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class."
This rule doesn't specifically say anything about spell slots. I think that there is room for interpretation either way, but a strict reading doesn't limit the cleric from preparing higher level spells.
"Spell Slots. You determine your available spell slots by adding together all your levels in the bard, cleric, druid, sorcerer, and wizard classes, half your levels (rounded down) in the paladin and ranger classes, and a third of your fighter or rogue levels (rounded down) if you have the Eldritch Knight or the Arcane Trickster feature. Use this total to determine your spell slots by consulting the Multiclass Spellcaster table.
If you have more than one spellcasting class, this table might give you spell slots of a level that is higher than the spells you know or can prepare. You can use those slots, but only to cast your lower-level spells. If a lower-level spell that you cast, like burning hands, has an enhanced effect when cast using a higher-level slot, you can use the enhanced effect, even though you don't have any spells of that higher level."
The relevant distinction made in this rule is the reference to the "Multiclass Spellcaster table." How distinct is this table from the "Cleric table" and the "Wizard table"? (Arguably, a single class character is eligible to use the "Multiclass Spellcaster table.")
The paragraph on cleric casting mentions the "Cleric table", but the paragraph on preparing does not. (The section for wizards to write a spell in their spellbook directly references the "Wizard table.")
A very strict reading does not limit a cleric from preparing spells of any level for which they have slots. If they can prepare the spell then they can ritually cast it.
More generally, should the rules be interpreted to allow clerics to prepare spells of a higher level than a spontaneous caster could? The rules aren't 100% clear.
When the DM has to make a call on an unclear rule, I would argue that the rule of fun needs to be taken into account. On the one hand, would it make the character too powerful and take away the fun for the rest of the party? Or if the character is going to use these higher level cleric spells to cast utility rituals that help the entire party, why not allow it?
I'm sorry, but you quoted the relevant text example in your rules quote.
This is clear. You prepare spells as though you were a single caster at a time: a cleric 1 can prepare level 1 cleric spells. A wizard 3 can prepare 1st and 2nd level wizard spells. There are even examples to help you.
This sentence only can exist if there is the possibility of having slots of levels for which you cannot know spells. The only way that can happen is if you read the first quoted sentence in the obvious (and strict and RAW) way. If one prepares spells as you suggest this sentence has no meaning.
Edit 2: Finally, making the leap that any character can use the MC spellcasting table to determine their spell slots available "as a single classed member" is a huge assumption with no mechanical support and therefore requires anything BUT a strict reading (unless you are saying that a cleric 1 uses row 1 from that table). "It doesn't say we can't" is never a good basis for a "strict" reading of RAW.
A single class character does not use the multiclass spell slot table, because a single classed character is not multiclassed. I hope that wasn't too complicated, but that concept is important for balancing multiclassing.
If the rule of fun were to supersede this RAW concept, it would allow a wizard 18/cleric 1/druid 1 to have access to the same spells as a level 20 Wizard, level 20 cleric, and level 20 druid and be able to prepare and cast essentially any spell in the game. A single level of mutliclassing should not gain 17+ levels of features from that 1 level.
World, the argument is... the single-classed rule for a Cleric (and also the other preparation casters) is "prepare anything you have a spell slot for", not anything resembling the known-spell casters which reads "the Spells Known column of the [Class X] table shows when you learn more [class x] spells of your choice." Contrast:
versus
If you read a known-spell caster's spellcasting feature "as a single-classed member of that class," it's clear that you know spells based on the numbers that show up in the class table, no matter what your spell slots look like for whatever reason. But when you read a preparation caster's spellcasting feature "as a single-classed member of that class," it tells you to look only at your spell slots. The multi-class spellcaster rules, which tell you to read your cleric spellcasting feature as if you're a single class cleric, don't actually stop you from preparing spells based on all of the spell slots you have available.
I'm in the camp that this is RAW despite being very very clearly not RAI (why would non-prep casters be punished in a way that prep casters aren't?) and I think you're not likely to win many points at a table trying to argue for it with your DM, but unless we get an errata which closes that loophole, Snake has a point.
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I'm going to make this way harder than it needs to be.
Why did you highlight two different sentences in the quotes when both have sentences that say "... of a level for which you have spell slots"? That is the definition of cherry-picking.
You bolded completely different parts of these rules. For sorcerer you bolded the sentence that says how many spell they know and when they learn them. Clerics also have rules for how many spells they can prepare (which you quoted but didn't bold) and when they can prepare them (which you did not include in your quote).
The whole sentence you quoted from cleric (since the partial bolded sentence seems irrelevant to your point) states what level spells a cleric can prepare. Sorcerers have a nearly identical sentence which you quoted but didn't bold.
Whatever claim you are trying to make about prepare casters would have to apply to both prepare casters and learn casters.
Luckily, it doesn't matter and your self contradicting claims are irrelevant because the RAW is clear.
So if you are single class the only thing you have to go on for what slot you have are:
I quoted different parts because they are laid out differently, not out of any attempt to obfuscate. The answer to what spells a known-caster can cast is “the spells that they know.” For a prepared caster, it’s “the spells that they prepare.” That’s why those are the sections I contrasted: a sorcerer knows the spells that their table allows them; while a cleric prepares spells based on their slots.
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I'm going to make this way harder than it needs to be.
But the sorcerer table allows them to learn spells of a level of which they have slots. It uses almost identical wording to clerics. The only difference is the timing that they choose spells, not the limitations on the spells they can choose.
I think it's a bit unfair to imply that the phrase "as if you were a single-classed member of that class" requires no interpretation. A first question might be: single class, but at what level? The rule alone doesn't answer this question, but the example does. There is need for a lot of interpretation on this rule, even if that interpretation feels like it is obvious. I don't think that it is unreasonable to show the rule to a DM and tell them that you want to ritual cast higher level spells.
Imagine a related but different case. It is entirely up to the DM whether or not a wizard can use another wizard's spell book. There is no RAW on this question either way. It is a common thing that happens in fiction, probably even in the forgotten realms books, and is a very fair question to ask of a DM. A wizard could use the spell book to cast higher level rituals than they would otherwise be allowed to, because wizards don't have the restriction that the ritual has to be prepared. I could imagine a lot of DMs allowing this.
"Ritual Casting
You can cast a wizard spell as a ritual if that spell has the ritual tag and you have the spell in your spellbook. You don't need to have the spell prepared."
That's from the wizard features, that being said you can still ritual cleric spells but you have to prepare them, further more the way cleric work is THEY KNOW ALL OF THERE SPELLS so if you have ONE level in cleric so long as you have a spell slot of the correct level you can prepare any of there spells, of you are a level 5 wizard and a level 1 cleric you can prepare up to 6 cleric spells (if you have 20 wisdom)
With all that information here is the answer your question: you can use any ritual cleric cleric spell so long as you have ot prepared and you have a appropriate spell slot to cast it with (even though a ritual cast doesn't consume a spell slot, you need access to spell slots of that level in order to prepare and cast it). Wizard rituals spells you can cast without having it prepared because WoTC really likes wizards
Actually there is a RAW answer to this question:
Simply put: you can only cast the spells in your spellbook, and can't even copy spells into it that are higher than you can cast.
When you multiclass from another class into wizard, you suddenly get handed a spellbook that contains six first level spells. This isn't necessarily a spellbook you wrote by hand, you certainly don't have to pay the gold cost to transcribe those spells, it's just a class feature you suddenly have. Some DMs might not like that and impose additional downtime hoops to justify the sudden appearance of this book, but a lot will be okay with saying "you found another wizard's spellbook." That isn't cutting corners, RAW there's no special cost or requirement for that book to spring into being, and JC has suggested that it's RAI as well. Snake isn't out on a limb that in a game where the DM has made that ruling once when you first multiclass into wizard, a player would have a good argument if they later find another higher level spellbook to tell the DM "this is my spellbook now, I'm trading up." If a wizard is able to embrace a book penned by someone else as "their spellbook" at level 1, it's hard to see what's stopping them from doing that later as well, if they're willing to leave their former book behind.
dndbeyond.com forum tags
I'm going to make this way harder than it needs to be.
It is extremely unreasonable to show the DM a rule but hide from him the next sentence that shows you how the game wants that rule to work. Maybe the writers of the book were self-aware enough to know that without an example, some people simply could not interpret the phrase "single-class member of that class." Who knows why its there, but any example in the rules text is there to clarify and show you how the rules work. The rules are to work the way the example works.
Your other example is unrelated, but I will address it. What you are describing has more to do with RP than mechanics. RAW again and again refer to your spellbook, but never describe how you got it. It only explains how you choose spells from your spellbook to cast and how you add to your spellbook. As long as you follow those rules, other things are just RP. You could in theory have a library of spellbooks from dead wizards if you wanted to RP that way, but you still need to follow the rules for how you add spells (6 + 2 more for each wizard level + gold and time for more) to your collection and how you select which to prepare (wizard level + int). In 5e you cannot just pick up a spellbook and cast any spell in it. You could, up to DM discretion, be allowed to say your spellbook is a collection of spellbooks that you didn't actually write - but I have no idea how you'd RP the 50 gp and 2 hrs of time for copying spells into it if you are saying you found it.
So, to add another fun layer... what if for Level 1 I chose the Cleric Domain of Knowledge... Thus granting Identify and Augury as Known/Always Prepared Spells?
In that case you can ritual cast Identify as a cleric, but you still don’t know Augury until you’re a third level cleric.
RAF and RAI, once you know those spells at the appropriate levels, I think that you can cast them at rituals.
RAW, you have to decide if the “a cleric spell with the ritual tag” means literally what it says or “a cleric spell for you” as the rules for casting with slots says. As I have mentioned, the rules indicate that there are two lists important to casters: the list of spells that they choose what they know or prepare from — the class list — and the list of spells that they can cast as a particular class. Unlike with casting using slots, this text doesn’t use words like “for you” or “cleric spell list.”