Codex Advocare + UMD = Profit?

[Jowgen]

The Codex Advocare is an item from Expedition to Castle Ravenloft


Activation: The book must be formally claimed in order to gain the benefit. Instructions for claiming the book are printed clearly on the flyleaf. The book can only have one claimant at any one time - the most recent claimant becomes the sole claimant. To claim the book, you must read the invocation descriptions from beginning to end (a task of some 8 hours) and then verbally claim the book. Once it is claimed, the book always provides its benefit to its owner, as long as the book is part of its owner's equipment.

Effect: You know one more least invocation than normal (you must be able to use least invocations in order to be able to utilize this ability).

The way I read it, anyone (fluent in infernal) can read the book and thus claim the book. After that, if the Codex is carried by the claimant, the Codex grants knowledge of a chosen invocation, although said Invocation can only be used by the claimant if the claimant has the ability to use least invocations. I think one can use UMD to emulate the Invocation class feature of a Warlock or DFA, so that the Codex grants the claimant the ability to actually activate the chosen invocation.

Use Magic Device lets you use a magic item as if you had the spell ability or class features of another class, as if you were a different race, or as if you were of a different alignment.

You make a Use Magic Device check each time you activate a device such as a wand. If you are using the check to emulate an alignment or some other quality in an ongoing manner, you need to make the relevant Use Magic Device check once per hour. [...]

Emulate a Class feature: Sometimes you need to use a class feature to activate a magic item. In this case, your effective level in the emulated class equals your Use Magic Device check result minus 20. This skill does not let you actually use the class feature of another class. It just lets you activate items as if you had that class feature.

Now I believe this works by RAW specifically due to how the Effect section of the Codex words the part about being able to utilize "this ability" (i.e. the least invocation). To be specific (as this is likelty the main point of contention): in addition to the "grant knowledge of invocation" benefit, the Effect section (as opposed to the activation section) includes a conditional ["able to use this ability" = yes/no] benefit, which is dependent on meeting the ["able to use least invocation" = True] qualfier. (side note: if the effect only said "grant knowledge of an invocation" then a DFA gaining knowledge of a Warlock invocation would not be able to use that invocation, as the DFA technically only has the ability to use Draconic Invocations. The "able to use this ability" = yes/no benefit removes that limitation.)

Or to put it more simply: you could also word the effect sentence as "As long as the activation conditions described above are met, you gain knowledge of a least invocation, and if you have the ability to use least invocations, you can also activate the ability that is said least invocation, as opposed to just knowing it but being unable to activate it".

So question 1, do you agree with my reading?

Question 2, provided you think this works, how would you maximize the usefullness?

EDIT: The RAW-viability of this exploit has been shut down after going down to the propositional calculus level.

[Jowgen]

I've had a look around, these are some of the uses/abuses I have been able to come up with so far:

- Arcane Caster level qualification. I'm not 100% on this, but afaik, Invocations, while being SLAs, do count as arcane spells of certains spells and come with an arcane caster level. This should be useful for mundanes and Divine Casters to qualify for things requring arcane CLs, such as Precocious Apprentice.

- I believe that, as written, the choice of invocation known is made at activation, and since the item stays activated for as long as it's claimed, it is not possible to change Invocation choice simply by making a new UMD check (check still required 1/hour to see whether the invocation works). It should, however, be possible to lend the book to someone else to claim (spending 8 hours) and then re-claim the book (again spending 8 hours), allowing a change in least invocation choice. It requires cooperation and is somewhat time-consuming, but being able to change invocations around like this gives a lot of flexibility.

- If the two cooperating indivuduals both have a Codex Advocare, it only takes 8 hours for both of them to switch invocations, as they could claim each other's Codex concurrently.

-The invocation-switching flexibility applies to: Aquatic Campaigns (Swimming the Styx), Social Campaigns (Beguiling Influence), Nature-heavy campaigns (Call of the Wild), Anti-Stealth/Detective camaigns (see the Unseen, All-seeing eyes, Serpent's Tongue, Track can be gotten from items), Demonweb pits camaigns (spiderwalk), and Knoweldge Heavy campaigns (Draconic Knowledge)

-The Invocations with the most general use IMO: Magic Insight, because at will detect magic and identify are handy; Baleful Utterance, because Shatter is real versatile; and Dark One's Own Luck, because Cha-synergy is a fun game to play.

- The fact that one needs to keep making UMD checks to maintain use of the Invocation might be a bit of a drag. The good thing is, there are several passive-benefit Invocations that have a 24 hour duration. Those can be activated at the start of the day and then the next 23 UMD checks do not matter.

[ATHATH]

"- If the two cooperating indivuduals both have a Codex Advocare, it only takes 8 hours for both of them to switch invocations, as they could claim each other's Codex concurrently."
"The book can only have one claimant at any one time - the most recent claimant becomes the sole claimant."

If you fail a UMD check, can you try to regain use of the invocation after an hour, or do you need to do the whole claiming thing all over again?

[Jowgen]

"- If the two cooperating indivuduals both have a Codex Advocare, it only takes 8 hours for both of them to switch invocations, as they could claim each other's Codex concurrently."
"The book can only have one claimant at any one time - the most recent claimant becomes the sole claimant."

If you fail a UMD check, can you try to regain use of the invocation after an hour, or do you need to do the whole claiming thing all over again?

Hmmm... tricky one.

If you fail the first UMD check post 8-hour read, you still activate the item, but do so as someone without the ability to use the now known invocation. Question is whether you can re-try the UMD while the Codex is still activated.

I'm going to go with yes. The rule requring a 1/hour check for ongoing use does not distinguish between successfull and failed checks. You need to keep making them regardless of failing or succeeding for as long as the item is active. If failing an hourly check means you can't use the Invocation for the next hour (though the codex remains active), it should follow that succeeding on the subsequent check re-activates the ability to use the invocation. If it didn't work like that, hourly checks would be pointless for continous items like this.

[Gruftzwerg]

Sry to say this, but imho this doesn't work as you think.

Yes, everybody can claim the book. And if you can use "least invocations" (or UMD it) you get to "know one more least invocation".
But that still doesn't give you the ability to use Invocations. It's the same as any effect that would grant you an additional "spell known". If you can't cast spells of the lvl, the known spell doesn't help you at all and doesn't work.
The same for invocations. You lack the "Invocations" ability warlocks and DFA have. Just being able to know "an additional one", doesn't effect the fact that you lack the ability to use "the additional one".

[Jowgen]

Sry to say this, but imho this doesn't work as you think.

Yes, everybody can claim the book. And if you can use "least invocations" (or UMD it) you get to "know one more least invocation".
But that still doesn't give you the ability to use Invocations. It's the same as any effect that would grant you an additional "spell known". If you can't cast spells of the lvl, the known spell doesn't help you at all and doesn't work.
The same for invocations. You lack the "Invocations" ability warlocks and DFA have. Just being able to know "an additional one", doesn't effect the fact that you lack the ability to use "the additional one".

Are you suggesting that "this ability" somehow refers to simply "knowing" the invocation? As in, knowing an invocation you can't use somehow being an ability? If so, I don't see how. :smallconfused:

[Gruftzwerg]

Are you suggesting that "this ability" somehow refers to simply "knowing" the invocation? As in, knowing an invocation you can't use somehow being an ability? If so, I don't see how. :smallconfused:

It doesn't say: "select an least invocation and use it as if you would know it".

it reads: "Effect: You know one more least invocation than normal (you must be able to use least invocations in order to be able to utilize this ability)."

UMD doesn't give you the ability to use "least invocations" in any way. you can fake it as requirement for the book to gain knowledge of an "least invocation". But you still can't use em.


edit: it's the same with "Turn Undead" related items. You can UMD "Turn Undead" as requirement. But that doesn't give you any "Turn Undead" attempts that you might be needing to use/activate the item.

[Jowgen]

It doesn't say: "select an least invocation and use it as if you would know it".

it reads: "Effect: You know one more least invocation than normal (you must be able to use least invocations in order to be able to utilize this ability)."

UMD doesn't give you the ability to use "least invocations" in any way. you can fake it as requirement for the book to gain knowledge of an "least invocation". But you still can't use em.


edit: it's the same with "Turn Undead" related items. You can UMD "Turn Undead" as requirement. But that doesn't give you any "Turn Undead" attempts that you might be needing to use/activate the item.

I believe the Codex distinguishes itself from items fuelled by Turn Unead and such, mainly due to how the Effect is worded (also, you don't expend any daily uses of anything with the Codex). If anything, I think it closer to the Woodwalk ASA (MiC p. 15). We are obviously in agreement that anyone can come to "know" the least invocation, so our disagreement seems to stem purely from how we read this line:

"You must be able to use least invocations in order to be able to utilize this ability"

You consider it to be a clarification of "knowing" an invocation not being the same as being able to use it.

I consider it another part of the items benefit, which should be read as "If you can use least invocations, you are able to utilize this ability."

From a RAI perspective, I'd find it strange for them to make an item that can explicitly grant an invocation known to non-invocation users, but offers no means for a non-invocation user to actually use that invocation. In that case, the better/obvious solution would be to make Invocation use a prerequesite for claiming the book in the first place, or word the effect as "If you have the ability to use least invocations, you gain one least invocation known more than normal".

[Zanos]

edit: it's the same with "Turn Undead" related items. You can UMD "Turn Undead" as requirement. But that doesn't give you any "Turn Undead" attempts that you might be needing to use/activate the item.
The UMD example actually had an item that required the character expend a turning attempt, so that's a pretty bad comparison.

For example, Lidda finds a magic chalice that turns regular water into holy water when a cleric or an experienced paladin channels positive energy into it as if turning undead. She attempts to activate the item by emulating the cleric’s undead turning ability. Her effective cleric level is her check result minus 20. Since a cleric can turn undead at 1st level, she needs a Use Magic Device check result of 21 or higher to succeed.

[Troacctid]

You don't need a Use Magic Device check to activate a Codex Advocare. Anyone can do it. You just spend 8 hours reading the book, and then verbally claim it. And that's it, it's activated. Similarly, anyone with a Warlock's Scepter can activate it with a swift action to gain a damage bonus on their eldritch blast, but it won't do jack if you don't have eldritch blast.

[Jowgen]

You don't need a Use Magic Device check to activate a Codex Advocare. Anyone can do it. You just spend 8 hours reading the book, and then verbally claim it. And that's it, it's activated. Similarly, anyone with a Warlock's Scepter can activate it with a swift action to gain a damage bonus on their eldritch blast, but it won't do jack if you don't have eldritch blast.

Indeed you can activate the codex no matter what class you are. You also have the not-mandatory-but-also-not-restricted option to make a UMD check, and upon success activate the codex as if you had the spell ability or class features of another class, specifically a DFA or Warlock's, who get a different effect when activating it. And as you say, Warlock Scepters work the same for anyone regardless of class; though most people can't benefit from it.

[Troacctid]

Indeed you can activate the codex no matter what class you are. You also have the not-mandatory-but-also-not-restricted option to make a UMD check, and upon success activate the codex as if you had the spell ability or class features of another class, specifically a DFA or Warlock's, who get a different effect when activating it. And as you say, Warlock Scepters work the same for anyone regardless of class; though most people can't benefit from it.
By your interpretation, a non-Warlock would gain the ability to use eldritch blast by activating a Warlock's Scepter with UMD.

[nolongerchaos]

I think a more apt comparison here is a Knowstone. Sure a Rogue could use UMD to trick it, and now she has, say, Magic Missile as a spell known... but since nothing in the items description says it allows the user the ability to cast spells if they previously lacked the ability, the Rogue still can't cast Magic Missile.

Likewise the Codex for the poor Rogue. She can claim it, and even pick up an invocation known. But the item doesn't really seem to grant the ability to use invocations, so she's up a creek in regards to doing anything useful with it, just like she would be with a Knowstone.

That's my reading anyway.

[Jowgen]

By your interpretation, a non-Warlock would gain the ability to use eldritch blast by activating a Warlock's Scepter with UMD.

I disagree, mainly since the Codex and Scepter function in such different ways.

The Codex grants a new ability if a prerequesite (i.e. able to use lesser invocations) is met. In contrast, the Scepter modifies the numerical value of a class ability, if that that ability is used. Also, the Scepter's does not change its function depending on who wields it (i.e. does not care if you have Elditch Blast), while the Codex does (i.e. does care if you have invocation use feature).


I think a more apt comparison here is a Knowstone. Sure a Rogue could use UMD to trick it, and now she has, say, Magic Missile as a spell known... but since nothing in the items description says it allows the user the ability to cast spells if they previously lacked the ability, the Rogue still can't cast Magic Missile.

Likewise the Codex for the poor Rogue. She can claim it, and even pick up an invocation known. But the item doesn't really seem to grant the ability to use invocations, so she's up a creek in regards to doing anything useful with it, just like she would be with a Knowstone.

That's my reading anyway.

That IS a more apt comparision (although spells are a bit more invovled with their castings/day and tables), and you are correct that for Knowstones "nothing in the items description says it allows the user the ability to cast spells if they previously lacked the ability". However, I believe the Codex to differ in this regard, as it's item effect description (as opposed to activation description) clearly states:

"you must be able to use least invocations in order to be able to utilize this ability"
which I believe should be read as
"If you can use least invocations, you are able to utilize this ability" (i.e. the invocation)

[Gruftzwerg]

I disagree, mainly since the Codex and Scepter function in such different ways.

The Codex grants a new ability if a prerequesite (i.e. able to use lesser invocations) is met. In contrast, the Scepter modifies the numerical value of a class ability, if that that ability is used. Also, the Scepter's does not change its function depending on who wields it (i.e. does not care if you have Elditch Blast), while the Codex does (i.e. does care if you have invocation use feature).
Sorry but it ain't a new ability. It enhances the ability "Invocations" from Warlock and DFA. And they are numerical values! You just get to know one more (+1) least invocation.





That IS a more apt comparision (although spells are a bit more invovled with their castings/day and tables), and you are correct that for Knowstones "nothing in the items description says it allows the user the ability to cast spells if they previously lacked the ability". However, I believe the Codex to differ in this regard, as it's item effect description (as opposed to activation description) clearly states:

"you must be able to use least invocations in order to be able to utilize this ability"
which I believe should be read as
"If you can use least invocations, you are able to utilize this ability" (i.e. the invocation)
and where do you get the ability to use least invocations?

UMD let's you fake a requirement to gain access to new abilities. But it can't fake the requirement as activation method (like with Turn Undead). It let's you count as if you had the requirement. Not as if you where "using"(!) the required ability.
You can count as "being able to use least invocations" to know an additional one. But that still doesn't help you to use (invoke) the known Invocation, cause you lack the ability to use least invocations (see Warlock & DFA lvl 1 in the table!).

[Troacctid]

I disagree, mainly since the Codex and Scepter function in such different ways.

The Codex grants a new ability if a prerequesite (i.e. able to use lesser invocations) is met. In contrast, the Scepter modifies the numerical value of a class ability, if that that ability is used. Also, the Scepter's does not change its function depending on who wields it (i.e. does not care if you have Elditch Blast), while the Codex does (i.e. does care if you have invocation use feature).
The problem is that you don't have that feature. And you can pretend to have that feature, but only for the purpose of activating it, not for anything else. And that feature is not required in order to activate it, which makes UMD moot.

The other problem is that it's an improvement to a class feature that you don't have.

[Jowgen]

Hmmm, it really looks like this reading of mine just isn't getting across... I shall give it one more shot.

The Codex's description has two relevant sections. The first section details the process of activating the codex, while the second section details what effect the Codex has following its activation. The activation requires the ability to read the Codex and the expenditure of time, followed by continued posession of the Codex.

Once the Codex is activated, it's Effect becomes active. The Codex's effect has two parts. The first part is that "You know one more least invocation than normal". If this were the extent of the codex's effect, then only Warlocks and DFAs, who can use any invocation they know at will, would be able to take advantage of the Codex.

However, the Codex's Effect has a second part; i.e. "you must be able to use least invocations in order to be able to utilize this ability". I read this to mean that you do not only "know" this invocation, but are also able to utilize this invocation; provided you meet the qualifying condition/requirement, which happens to be having the ability in the first place (which is admittedly redundant).

I therefore believe the whole Effect can be read/pharsed as such:

"Effect: You know one more invocation than normal and you can use this invocation in the manner invocations are used, provided you meet the qualifying condition that is being able to use least invocations".

Emulating the ability to use least invocations, while not mandatory for the activation of the Codex, can be done during the activation of the Codex (as UMD doesn't limit you to only Emulting things that are nessecary); so as to meet the requirement needed for the Codex's effect to not only include the "known" part, but the be able to utilize part as well.

I completely understand if you still don't think this is how it's meant to work, or that it's not the best way to read this text; but can you at least see where I am coming from? If not I shall desist from trying to explain my reasoning herein.

[Troacctid]

Your reading is getting across just fine. It just doesn't match the text.

The UMD rules are very clear:

Sometimes you need to use a class feature to activate a magic item. [...] This skill does not let you actually use the class feature of another class. It just lets you activate items as if you had that class feature.
What you are trying to do is outside the scope of what UMD allows you to do. It lets you activate items that require a class feature in order to activate them. That's it. You can't emulate a class feature for any other purpose than that.

[daremetoidareyo]

I think a possible bridge to understanding is here:

"If you are using the check to emulate an alignment or some other quality in an ongoing manner, you need to make the relevant Use Magic Device check once per hour."

You need to continuously trick the magic of the book into thinking that you are a legit target for its effect because its effect is contingent upon the character knowing how to use least invocations as a class feature.

I'm inclined to say that Jowgen's reading of UMD is permissive of this rules blurp.


Check
You can use this skill to read a spell or to activate a magic item. Use Magic Device lets you use (not necessaril limited to 'activate') a magic item as if you had the spell ability or class features of another class, as if you were a different race, or as if you were of a different alignment.

[Troacctid]

That would still leave the other problem, which is how are you adding an extra invocation to your invocations known if you do not have the invocations known feature? In some situations, you'd be able to say, "Well, the text doesn't specify whether it's treated as zero or as a null value that cannot be added to, so it's the DM's call," but in this case the text does clarify how it works, and it clearly says you do not gain any benefit. So you're back in the same situation as trying to UMD armor of the beast to gain the ability to wild shape—it doesn't work.

[Cosi]

I think a more apt comparison here is a Knowstone. Sure a Rogue could use UMD to trick it, and now she has, say, Magic Missile as a spell known... but since nothing in the items description says it allows the user the ability to cast spells if they previously lacked the ability, the Rogue still can't cast Magic Missile.

Actually, by RAW you can totally UMD the "cast a spell" part of the Knowstone. It says you can use it if you have the spell on your list (a class feature you can emulate) and have a spell slot to expend (also a class feature you can emulate). At a glance, it doesn't look like the Codex works the same way, because it just talks about giving you the "know" ability, not the "use" one.

[Jowgen]

That would still leave the other problem, which is how are you adding an extra invocation to your invocations known if you do not have the invocations known feature? In some situations, you'd be able to say, "Well, the text doesn't specify whether it's treated as zero or as a null value that cannot be added to, so it's the DM's call," but in this case the text does clarify how it works, and it clearly says you do not gain any benefit. So you're back in the same situation as trying to UMD armor of the beast to gain the ability to wild shape—it doesn't work.

Well this awkward... :smallredface:

"It does not, however, grant that ability if you do not already possess it." can in my opinion be taken to mean that "If you already possess that ability (i.e. Wildshape), it does grant it"; which would normally be rendundant, although so if you emulate Wild Shape, then as far as the Armor is concerned you do have it, meaning it would grant it. I think this perfectly falls within UMD of letting you use magic items as if you had a class ability, even though you can't use that class ability.

Now I do, however, concede in regards to the null value aspect. I think it's perfectly RAW-reasonable for a DM to rule that you can't gain things like Known Spells or Invocations or whatever unless you actually have the ability to use those beforehand. It's a rather silly notion in the first place that only comes into play due to pedantic RAW-reading sourced loopholes like the one I am trying to exploit here.




Actually, by RAW you can totally UMD the "cast a spell" part of the Knowstone. It says you can use it if you have the spell on your list (a class feature you can emulate) and have a spell slot to expend (also a class feature you can emulate). At a glance, it doesn't look like the Codex works the same way, because it just talks about giving you the "know" ability, not the "use" one.

I do not see this working, as the Knowstone specifies that the beneficiary needs to "use his spell slot to cast the spell normally". If the Codex stated something akin to "granst knowledge of one invocation, which you can then use by means of your Invocation class feature" I would not be arguing for this.

[Cosi]

I do not see this working, as the Knowstone specifies that the beneficiary needs to "use his spell slot to cast the spell normally". If the Codex stated something akin to "granst knowledge of one invocation, which you can then use by means of your Invocation class feature" I would not be arguing for this.

Yes, and as the example with the chalice makes clear, UMD allows you emulate not just having a class feature, but expending it as well. As you note, the Knowstone explicitly includes the ability to expend a spell slot to cast the spell contained in it. In any normal case, this is redundant -- if you know the spell (the other feature of a Knowstone), you can simply use a spell slot to cast it because you can cast your known spells. However, the fact that it is phrased as a function of the item means you can use UMD to emulate a class feature for that function.

[Troacctid]

Well this awkward... :smallredface:

"It does not, however, grant that ability if you do not already possess it." can in my opinion be taken to mean that "If you already possess that ability (i.e. Wildshape), it does grant it"; which would normally be rendundant, although so if you emulate Wild Shape, then as far as the Armor is concerned you do have it, meaning it would grant it. I think this perfectly falls within UMD of letting you use magic items as if you had a class ability, even though you can't use that class ability.

Now I do, however, concede in regards to the null value aspect. I think it's perfectly RAW-reasonable for a DM to rule that you can't gain things like Known Spells or Invocations or whatever unless you actually have the ability to use those beforehand. It's a rather silly notion in the first place that only comes into play due to pedantic RAW-reading sourced loopholes like the one I am trying to exploit here.
In this case you don't need the DM to intervene, because the text itself already clarifies that it works like the null, not the zero.

There are many examples of items like this that I could point to. You can't UMD a dragon spirit amulet to gain a draconic aura. You can't UMD an armband of confrontation to gain knight's challenge. You can't UMD a rogue's vest to gain sneak attack. Etc.

[Jowgen]

In this case you don't need the DM to intervene, because the text itself already clarifies that it works like the null, not the zero.

There are many examples of items like this that I could point to. You can't UMD a dragon spirit amulet to gain a draconic aura. You can't UMD an armband of confrontation to gain knight's challenge. You can't UMD a rogue's vest to gain sneak attack. Etc.

Which text clarifying null over zero would you be refferring to? I was under the impression that, generally speaking, this a big grey area.

As for these other items... *goes to check* Dragon Spirit Amulet only affects currently active auras, so that one's out. Rogue's vest is out, because while you can emulate having the sneak attack class feature, you can't emulate making an actual sneak attack, to which the extra 1d6 could apply. Armband of Confrontation also only works on an actual fighting challange, so it's out.

On the up-side, I now have a new project of scouring for items with abusable wordings akin to the Codex and Beast Armor :smallbiggrin:


Yes, and as the example with the chalice makes clear, UMD allows you emulate not just having a class feature, but expending it as well. As you note, the Knowstone explicitly includes the ability to expend a spell slot to cast the spell contained in it. In any normal case, this is redundant -- if you know the spell (the other feature of a Knowstone), you can simply use a spell slot to cast it because you can cast your known spells. However, the fact that it is phrased as a function of the item means you can use UMD to emulate a class feature for that function.

Ah, I see. I myself do not subscribe to the school of thought that UMD allows for the expenditure of "virtual class feature uses"; but if you're someone who does based on the Chalice example... I suppose I can see it working (not big into caster optimization/shenanigans myself)

[Troacctid]

Which text clarifying null over zero would you be refferring to? I was under the impression that, generally speaking, this a big grey area.
The part that spells out what happens if you don't have access to least invocations.

[Cosi]

Ah, I see. I myself do not subscribe to the school of thought that UMD allows for the expenditure of "virtual class feature uses"; but if you're someone who does based on the Chalice example... I suppose I can see it working (not big into caster optimization/shenanigans myself)

There's not any ambiguity in the text. RAW is very explicit that you can emulate not only having, but using a class feature. That generates results that are stupid, and fairly broken, but there's no wiggle room where maybe it doesn't work that way.

[nolongerchaos]

Yes, and as the example with the chalice makes clear, UMD allows you emulate not just having a class feature, but expending it as well. As you note, the Knowstone explicitly includes the ability to expend a spell slot to cast the spell contained in it. In any normal case, this is redundant -- if you know the spell (the other feature of a Knowstone), you can simply use a spell slot to cast it because you can cast your known spells. However, the fact that it is phrased as a function of the item means you can use UMD to emulate a class feature for that function.

...I always forget how terrible that chalice example is.

Let's do a little math. 4th level spell Knowstone= 16k... now we've got Black Tentacles at will, if you can make UMD checks, since the item thinks you're using spell slots you don't even have, thanks to UMD.

...so a Greater Invocation at will (weighing 4k gp less VS missing out on 2d6 cold damage from the invocation equivalent), for less than the Codex, which itself only replicates Least Invocations.

What a silly conclusion to come to, but I can see how RAW can lead you right there.

[Jowgen]

The part that spells out what happens if you don't have access to least invocations.

Oh, you meant in this specific case, I thought you were talking generally. Okay, I think I may have a way that might allow us to get closer to common ground. Below there are two permutations of the Codex-Crux sentence that I consider to be synonymous with the original.

Original sentence: You must be able to use least invocations in order to be able to utilize this ability

Permutation 1: You must have the warlock/dragonfire adept's ability to use known least invocations in order to be able to utilize this additional invocation you now know.

Permuation 2: If you have the warlock/dragonfire adept's ability to use known least invocations, you are able to utilize this additional invocation you now know.

So the first question is whether we can agree on these permutations being synonymous with the original. If yes, then it's only one step of interpretation that seperates us.

[Troacctid]

They are not synonymous with the original.

[Bakkan]

Oh, you meant in this specific case, I thought you were talking generally. Okay, I think I may have a way that might allow us to get closer to common ground. Below there are two permutations of the Codex-Crux sentence that I consider to be synonymous with the original.

Original sentence: You must be able to use least invocations in order to be able to utilize this ability

Permutation 1: You must have the warlock/dragonfire adept's ability to use known least invocations in order to be able to utilize this additional invocation you now know.

Permuation 2: If you have the warlock/dragonfire adept's ability to use known least invocations, you are able to utilize this additional invocation you now know.

So the first question is whether we can agree on these permutations being synonymous with the original. If yes, then it's only one step of interpretation that seperates us.

Permutation 1 and permutation 2 are not logically equivalent.

Permutation 1 says: IF (You do not have the warlock/dragonfire adept's ability to use least invocations) THEN (You may not use this additional invocation)

Permutation 2 says: IF (You have the warlock/dragonfire adept's ability to use least invocations) THEN (You may use this additional invocation)

These are not equivalent, since in general the propositons
IF (NOT A) THEN (NOT B)
and
IF A THEN B
are not equivalent.

[Jowgen]

Permutation 1 and permutation 2 are not logically equivalent.

Permutation 1 says: IF (You do not have the warlock/dragonfire adept's ability to use least invocations) THEN (You may not use this additional invocation)

Permutation 2 says: IF (You have the warlock/dragonfire adept's ability to use least invocations) THEN (You may use this additional invocation)

These are not equivalent, since in general the propositons
IF (NOT A) THEN (NOT B)
and
IF A THEN B
are not equivalent.

First off, kudos on your propositional calculus. Secondly, before delving into the issue of the equivalency of the permutations, may I ask whether you consider either of the two to be synonymous with the original sentence?

[Gruftzwerg]

First off, kudos on your propositional calculus. Secondly, before delving into the issue of the equivalency of the permutations, may I ask whether you consider either of the two to be synonymous with the original sentence?

You should only rely on synonymous if everything else fails. And this is not the chase here. Imho the rules and the text is obvious. Sorry but you are just trying to twist words and reading more into it as there is.

[Bakkan]

First off, kudos on your propositional calculus. Secondly, before delving into the issue of the equivalency of the permutations, may I ask whether you consider either of the two to be synonymous with the original sentence?

Proposition 1 is equivalent to the original, assuming that the warlock and dragonfire adept class features are the only way to use least invocations, which I believe is the case. The statement is slightly ambiguous in what it means by "this ability", but the most reasonable reading I see is that "this ability" refers to the newly learned invocation.

By way of analogy, consider the proposition "You must hold a Ph.D. in order to teach at Princeton University". We can determine the logical structure of this sentence by considering what it tells us about the truth values of its component elements if we assume it to be true.

If you hold a Ph.D. and teach at Princeton University, then the situation is consistent with the statement.
If you hold a Ph.D. and do not teach at Princeton University, then the situation is still consistent with the statement, as it says nothing about people who don't teach at Princeton.
If you do not hold a Ph.D. and teach at Princeton University, then this contradicts the above statement, i.e. this situation cannot occur.
If you do not hold a Ph.D. and do not teach at Princeton University, then the situation is consistent with the statement.

Thus the statement "You must hold a Ph.D. in order to teach at Princeton University" is equivalent to the statement "You cannot both teach at Princeton and fail to hold a Ph.D.", which is equivalent to the statement "If you teach at Princeton, then you hold a Ph.D."

There was of course nothing special about the specific proposition I used, and as a general rule, the sentence "A in order for B" is logically equivalent to "IF B THEN A", which is in turn logically equivalent to "IF (NOT A) THEN (NOT B)". If the original sentence, A is "You are able to use least invocations" and B is "You can use this ability".

[Jowgen]

The statement is slightly ambiguous in what it means by "this ability", but the most reasonable reading I see is that "this ability" refers to the newly learned invocation.

I agree that this part isn't as clear as I would like, but yeah, I can't actually conceive any other interpretation.


By way of analogy, consider the proposition "You must hold a Ph.D. in order to teach at Princeton University". We can determine the logical structure of this sentence by considering what it tells us about the truth values of its component elements if we assume it to be true.

If you hold a Ph.D. and teach at Princeton University, then the situation is consistent with the statement.
If you hold a Ph.D. and do not teach at Princeton University, then the situation is still consistent with the statement, as it says nothing about people who don't teach at Princeton.
If you do not hold a Ph.D. and teach at Princeton University, then this contradicts the above statement, i.e. this situation cannot occur.
If you do not hold a Ph.D. and do not teach at Princeton University, then the situation is consistent with the statement.

Thus the statement "You must hold a Ph.D. in order to teach at Princeton University" is equivalent to the statement "You cannot both teach at Princeton and fail to hold a Ph.D.", which is equivalent to the statement "If you teach at Princeton, then you hold a Ph.D."

I bow before the power of your logic, and I think I see where I went wrong.

One can emulate the "must have" prerequesite, so that not having it no longer bars you from using the Invocation, but it doesn't say that simply meeting that prerequesite (i.e. getting around that bar) is enough to get you the "prize". With UMD, you're no longer prohibited from using the known invocation, but that doesn't nessecarily mean you are at liberty to do it. Kind of a more subtle twist on the classic "just because it doesn't say you can't doesn't mean you can".

Personally, I could still see the average DM not caring about this distiction in this instance (i.e letting the permutations equate without complaint) and thus allowing the Codex exploit (especially considering the high skill and gp investment for what largely ammounts to some 1st-2nd level spell at-will SLAs). But, from a RAW perspective, this does shut it down in my book. Thank you for helping me realize.