Requirements to Cast a Spell
In L5R, to cast a spell you need Two things:
- The innate capacity and knowledge to convince the kami to do magic of that level. Ie your effective school rank must be equal to or higher than the spells rank.
- Affinity raises your effective school rank by one, for one particular Ring (see page 164)
- Deficiency reduces it by one.
- You must correctly say (or pray really) the spell
- to do this you must read from a scroll as spells are very complex.
- or you can have memorised the spell completely. This costs pay XP equal to its mastery rank, see sidebar page 164. "How are Spells cast"). Memorising replaces Reading (not learning)
- you learn 3 new spells at each time you gain a school rank, they must be of a mastery level you can cast (see Sidebar page 105). You are assumed to gain scrolls for these.
- your School entry will list under spells (below technique) what spells you start knowing.
You can however get around some of these restrictions by casting Commune and using the Importune Emphasis of the Spellcraft skill -- basically convincing the kami to do it anyway.
Can you learn new spells without increasing school rank? -- Maybe.
Gaining new spells without going up in skill rank is dubious. Your school entrusts you with these spells. Personally. A sensei of your school will likely have personally shown them to you.
- remember learning new spells in L5R involves increasing school rank, which normally involves going back to your Clan for more training (after, and separately to, raising your insight))
- The rules (as far as I know) never speak about whether it is possible to cast spells using scrolls that belong to another Shugenja. They might be in cipher, potentially, but that is never made clear.
- There is no price scrolls in the equipment section
- For balance reasons you may decide that you should not (or that you should) make it possible to use other scrolls you find (or Loot -- though that is pretty dishonourable.)
- Most Schools (eg Bushi) only gain one new cool ability each time they gain a School Rank. Shugenja gain 3. This is balanced by the fact that Shugenja can only use theirs a fixed number of times per day.
Strictly speaking, yes, but it involves intense shenanigans.
First, the Magical Training feat from Player’s Guide to Faerûn gets you in the door with three cantrips from the Sor/Wiz list, cast as sorcerer or wizard would (your choice). You count as a spellcaster with caster level 1st (minimum). You must be an elf or human, and must be from a specific region of Faerûn (though this requirement ought to be waived or adapted if not playing in the Forgotten Realms).
From there, there are tricks to improve your spellcasting:
Precocious Apprentice from Complete Arcane pg. 181 (not with the rest of the books’ feats) gets you a single 2nd-level sor/wiz spell. Since both Magical Training and Precocious Apprentice can only be taken at 1st level, you’ll need to be human (or be using the Flaws variant rules from Unearthed Arcana).
Dragon’s Blood Pool from Complete Mage grants you access to a 1st- to 3rd-level spell slot for one year.
Heighten Spell allows you to shove cantrips into that spell slot.
Sanctum Spell, also in Complete Arcane but with the rest of the feats this time, can let your spells count as one level higher.
Versatile Spellcaster from Races of the Dragon allows you to combine two spells of one level to get a spell of the next level:
Combine two cantrips-as-1st-level-spells (due to Sanctum Spell) into a 2nd-level spell slot. Fill using Heighten on one of the cantrips, or (maybe) using the spell you chose for Precocious Apprentice.
Combine that with the 2nd-level spell from Precocious Apprentice to get a 3rd-level spell slot. Fill using Heighten.
Combine that with the 3rd-level spell from Dragon’s Blood Pool to get a 4th-level spell slot. Fill using Heighten.
Earth Spell from Races of Stone can allow you to Heighten a spell such that it gets a +1 effective spell level above the slot you put it in, so your spell counts as a 5th-level spell in the end.
There are more. See the Early Entry Handbook for more details.
But as you can see, this is very sketchy stuff, and you don’t actually know spells of the various levels you have access to; you just get to count lower-level spells as higher level. This is good for e.g. getting into prestige classes, but not very valuable in adventuring most of the time. You only really know three cantrips and a single 2nd-level spell, and the tricks break down if you’re not in your sanctum.
If you really want a non-spellcaster with extremely minimal spellcasting, Magical Training plus Precocious Apprentice is probably your best bet. I wouldn’t bother with the rest. Maybe the Dragon’s Blood Pool, but as a magical location you’d have to find it first, and that might be tricky.
But really, it’d be much better to play a duskblade or something.
Best Answer
Yes, by making a caster level check and meeting some requirements
The relevant rules are all in the Magic Items - Scrolls section of the DMG. Here's a copy from the SRD. There are two steps:
Read Magic is a level 0 Cleric spell, so your player can prepare and cast it to perform this step. They could also use the Spellcraft skill instead, but a DC 23 Spellcraft check can be difficult for a level 2 Cleric to make.
Assuming you're giving out a Divine scroll, this is no problem.
Clerics have Remove Disease on their spell list, so this is no problem.
Remove Disease is a third level Cleric spell, so your Cleric requires 13 Wisdom to meet this requirement.
Being a third level spell, the caster level requirement is 5. You can tell that because it's a third level spell, and Clerics get third level spells at level 5.
Your Cleric is likely a level 2 Cleric, thus has a caster level of 2. That isn't sufficient to meet this requirement, so your Cleric will have to make a caster level check of DC 6 (5 + 1). A caster level check is 1d20 + caster level, or 1d20+2. Only needing a a total of 6, a 4 or better on the dice will let your Cleric cast the spell. Those are good odds.
At Cleric level 5, your player can cast the scroll without having to make the check.
If your Cleric doesn't meet the other requirements, or someone else wants to use the scroll, they have to use Use Magic Device instead.