Shattered Kingdoms

How much of a difference is there using cheap scrolls and good scrolls? Like with spells such as charm person? And also, how do you tell the difference between the two? I've just been buying the most expensive ones.. is that even accurate?

It's not accurate anymore. With the way the economy code is working these days, the most expensive will almost always equate just to the most popular. That doesn't mean the best. Identify is what will tell you best from worst, based on "strong spells of ." or "weak spells of .", etc.

Finding the most powerful bought scrolls in the game is a long and oft-times challenging process that can take awhile without an IC mentor. My recommendation is to ask around in-character, and learn that way.

As to the first part of your question, there's a lot of debate on the subject. The two arguments go like this:

1) If you're going to get hit with a scroll spell, given the total amount of art available to scroll-use and the relative strength of scroll spells vs cast spells, then you're probably going to get hit with a spell from just about any scroll no matter what strength it is.

2) The strong scrolls are worth the effort it takes to find/get them, period.

Now, that's for offensive spells. For defensive spells, I would most likely tell you that the moderately strong to very strong scrolls are worth the effort. They'll determine, for example, the duration of a death shroud, or the number of mirrors you get for a mirror image. Ultimately, though, it will depend on what you intend to have the defensive spells for. If they're invis scrolls for a quick jaunt through territory with weak but annoying NPCs, then weak is fine. If it's for top-tier pk and CRS action, then stick with as strong as you can get your hands on.

weak scrolls for polymorph/mirror image/rift/teleport/etherealform/gate
powerful scrolls for petrification/charm person/finger of death/fear

Its my understanding that the power level of spells in consumable items relates to the Caster Level of the item in question, much as a wand, portion, or any other spell trigger, spell completion, or use-activated item would have its own associated caster level in D&D (staves notwithstanding -- I'm pretty sure they have power levels in SK last time I checked.)

My assumption is that caster level affects the duration, effectiveness, and tenacity of a spell. Just an assumption, though.

So the question is: do you want to go through the effort of getting a higher caster level on that spell? Depends on the use and the spell, I'd say.

I brew Recall in the cheapest vials I can find. If the barbarian chugging it happens to resist, then, well, that's his loss.

No. It's item level dependant. I understand it used to be caster-level, but that was changed long before I started playing.

magic resistance does not vary based upon spell level.

The important factor is level of the item, not level of the caster using the iem. Back in the day scrolls used to run off of player level as opposed to item level, but no longer.

Wow, I heard that somewhere before.

Higher level spells don't have less of a chance to be resisted.
Staves and scrolls used to be dependant on the reciter/brandisher/zapper level, but they were changed a very long time ago to be based on the strength of the item being used (underpowered, moderate, overpowered).
In the same way, brewing, scribing and recharging spells doesn't take into account the brewer, scriber, or enchanter, but the strength of the vial, scroll, or recharged item.

I don't know if it's worth unnecessarily complicating things, but Dulrik pointed out to me in a thread a while back that user level still affects scrolls, etc. You end up getting the lower of the two (user level, item level).

The reason why everyone is referring to item level is that in most (particularly PK) cases your level is going to be higher than the item's level.

While on the subject, why is it that staves require you to be their level before you being able to use them at all? Doesn't this go against the spirit of "complete character at master."

Although I see logic in your comments, I quiver in fear at the idea that Dulrik spends his apparently mega-limited coding time on things such as these instead of big game changes that could be very quick to implement .