Review a mechanic for allowing weaker Spell Scrolls even if not on class spell list

Question

I am a new GM so I would like to get some feedback on me "relaxing" the Spell Scroll class requirements. Basically if it makes sense and is not something I might regret in the long run.

The standard spell scroll rules as in the DMG say:

If the spell is on your class's spell list, you can read the scroll and cast its spell without providing any material components. Otherwise, the scroll is unintelligible.

I've decided to replace that "Otherwise" part by:

1. adding an Intelligence (Arcana) check before attempting such a cast (scroll still consumed on fail),
2. requiring material components,
3. and lowering the scroll DC and spell attack bonus if not on class.

I've also added separate rules for full casters (Warlocks included), half casters (e.g. Ranger, Paladin), and non casters.

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The conditions I went with are:

1. full caster:

   • perform DC a 6 + (3 * [spell level]) Intelligence (Arcana) check
   • needs material components (spellcasting focus not applicable)
   • scroll spell DC is [scroll description DC] - 3 and spell attack bonus [scroll description spell attack bonus] - 3

2. half caster:

   • perform DC a 11 + (3 * [spell level]) Intelligence (Arcana) check
   • needs material components (spellcasting focus not applicable)
   • scroll spell DC is [scroll description DC] - 3 and spell attack bonus [scroll description spell attack bonus] - 3

3. non caster:

   • perform DC a 11 + (3 * [spell level]) Intelligence (Arcana) check
   • needs material components (spellcasting focus not applicable)
   • scroll spell DC is [scroll description DC] - 6 and spell attack bonus [scroll description spell attack bonus] - 6

If the spell level is higher than what the class could normally cast, apply the rules of the following category (i.e. full casters are treated as half casters, half casters are treated as non casters).

Cantrip [spell level] in the formulas is 0, meaning that even a barbarian will find casting cantrips from scrolls easy (if they can read that is), but anything beyond level 3 will be very hard or impossible to achieve.

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Just for context why I'm doing this. I'm running a pre-written 5e adventure with a group that doesn't have a lot of casters. I have noticed that some encounters can drastically shift in difficulty depending on what casters and spells are available, and decided to add in a few level 1 scrolls as a just in case.

To be more specific (spoiler in case my PCs are reading this):

There is an Intellect Devourer encounter I need to keep in, so I added a couple Protection from Evil and Good scrolls in the loot of a session before. However, after the session I noticed that only one player can cast it and I am unsure if they will be conscious for that encounter.

Answer 1

It is useless.

If I found scroll I cannot use normally, then, after consulting these rules, I would sell it or give it away.

I'll start with the common second condition. What it really says is "you can use it only with a specific kind of a spellcasting focus", because a component pouch is functionally indistinguishable from other kinds of spellcasting foci, and can be treated as another kind of them. And if any player starts to buy and track every non-priced material component manually, I would check if they are okay.

Now let's consider "that even a barbarian will find casting cantrips from scrolls easy " claim.

Arcana is not a class skill for barbarians and Intelligence is a dump stat for them. At best average barbarian will have a +0 modifier on scroll check, which makes him succeed 50% of the time against DC of 11.

Now apply penalty to the DC and it drops from 13 to 7. An average human without any training or distinguising features with +0 modifier to saves will save 70% of the time. For many enemies DC that low means that you won't even have to roll a save, because they will save even on 1.

The same can be said about cantrips requiring an attack roll: your final modifier is -1, so you have a 50% chance to hit the naked man from the previous test standing still.

Negative modifiers to saves and AC below 10 are extremely rare, so your barbarian has at best 50% * 30% = 15% or 50% * 50% = 25% for his casting to affect anyone. At best.

Let's check your intended use case.

Protection from Evil and Good does not require either save or an attack roll. This is good: such spells are the only ones, which can theoretically be used without it feeling like you are playing Russian Roulette with 5 to 1 chances of wasting an action instead of casting a spell. Non-full casters will have to beat DC14, our barbarian has a whopping 35% chance to actually cast it! It is only 3 scrolls used up for every succesfull casting on average! As nor Intelligence nor Arcana are usually prioritised by non-full caster classes which cannot normally cast Protection from Evil and Good, they would not fare much better. I expect the chance for them to succesfully cast to be no more than 50%.

On the other hand, full casters would fare better, having to beat only DC9, which gives 60% chance to cast even at +0 modifier, and if something is boosting it, even more!

Finishing thoughts

The only worthwhile use with your rules is non-save, non-attack based spells of a level no higher than 3 when used by full casters. At spell level 3 you have to beat a DC15 check in your non-primary ability just to use it. Any higher and it goes from "worth a try" to "just sell it and hire someone to cast it for us".

Answer 2

You're making this overly complex

It's got a lot of "moving pieces" that will slow down the game.

One problem is; what is a "full caster", "half-caster", or "non-caster"? These are not defined terms in D&D 5e, so you'll have to be more specific. What happens with multi-class characters? Are they "full"? "half"? "three quarters"? Assuming you can nail down that answer, the DC to attempt to cast the spell and the DC to save against the spell can be precalculated. But then you run into the next problem.

Intelligence is usually a dump stat unless your character requires it. And Arcana is typically ignored as a skill as well. Meaning that a large portion of characters are going to be terrible at this check and it will be more likely that the character will fail than succeed.

Add to that the need for spell components. How would a character that doesn't know how to cast a spell figure out what spell components they would need? They are already baked into the scroll so it's not like they would be explained anywhere on the scroll. Would a regular component pouch that a typical caster uses work? Or would they need to find just that one item (or set of items) in order to cast the spell. This also means that the characters have two or more items to pass around in order to cast the spell. If used in combat, that means extra juggling and wasting of Action economy.

Picture this; the wizard has the scroll and the components since they have the best chance of getting off the spell. But in combat the wizard is incapacitated, so the fighter needs to use the scroll. Per the rules of combat, you can [...] interact with one object or feature of the environment for free. Meaning the fighter can grab the scroll OR the components for free but not both. Meaning it will take a full Action to get everything. The following round, they can "Use an object" as an Action to cast the scroll. At best (10 Int and no Arcana proficiency), it's a DC 14 to cast the 1st level spell. So about a 75% chance that after all this, the whole thing fails.

And what about failure?

The whole reason this system is being designed is your fear that without someone being able to cast these spells, the party will be in trouble. But if the odds are stacked in favor of the party failing to cast the spell in the first place, what are you really gaining? False hope?

Make something for the occasion

A big problem is that once used, the scroll is done. If it fails, it wasted time and resources (spell components), and you'll need to keep resupplying the party with more.

So instead, create limited use magic items like a wand or a potion. This will greatly simplify things as there are already rules established for using magical items. They do not have chances of failing before use, so everyone has the same chance of succeeding.

Potions can grant temporary effects to mimic certain spells like a protection spell and can/will have a reasonably fixed DC. Potions are one-use-only like scrolls, but there is no chance to fail making potions a better choice. Just give out 2-3 and use them as needed.

Similarly a wand have a fixed DC and will have a few charges a day to mimic the spells you need.

Answer 3

As a system DND5e was made with intention of making roleplaying easier for both players and GMs and more casual. The intentionally removed a lot of complex things, simplifying a lot of things, making DND5e much easier system.

Your idea doesn't look fitting into DND5 philosophy. It introduces a complex system, requiring complex calculations, which is likely to confuse your players.

Also, your idea goes against some of rules - material components and everything are expended at scroll creation and are not needed to be used a second time, when casting spell from scroll.

In general - if you want characters to be able to cast spell from scrolls - use a simple check. For example - expand the rule saying that to cast a spell that is above his maximumx spell level caster must succeed in DC10+spell's level ability check to everyone.

Also, if you and your players want things to be more complex - you may want to try other, more complex game systems, like Pathfinder, for example.

Answer 4

It is generaly a bad idea to introduce changes to the rules until you actually know the system. And as a new DM you definitely don't know it. Your suggestion is overly-complicated (and would be overly-complicated for 3.5/pathfinder, which are drastically more complex systems than 5e) and doesn't actually solve your problem. Your players won't use scrolls if there are better than even odds they will just waste their action AND a scroll.

If you believe this encounter really needs this spell then do something else to give them this tool. Just give them potions instead of scrolls. Or introduce a friendly NPC caster. Or something. But having an encounter that counts on party using a specific spell it treading on dangerous waters. Even in a perfect 'nothing goes wrong for the party' session it is quite possible they won't think about using that spell. In fact, you should never bet on players doing what you expect them to do! So rather than trying to change the rules you should try to change your encounter.