We’re level 8, we’ve been told that there is an imposter in the royal court and I have a brilliant plan: buy a Scroll of True Seeing and use it to give the queen truesight so she and her mighty court can defeat the imposter, one of my character’s long-running enemies. I figure I’m only a few levels away from 6th level spells, how hard could it be to successfully use the scroll. A DC 16? And its only an ability check? No proficiency bonus? No taking into account how close I am to having the spell myself? I have a 50% chance of succeeding in using this scroll, and that only because I have taken an ability score improvement every chance. Have D&D scrolls always been this hard to use when you actually care to use them? When its a spell you don’t already have access to?
So naturally, I go into my 1e books to see how scrolls used to work, you know, back when spell access was more limited and scrolls were actually used by people. Sure enough, it works exactly as I would have expected: 5% chance of failure per level the caster is lacking to be able to cast the spell. There’s the small matter of a chance of reverse or harmful effects on failure, but we’ll ignore that. The graphs below should help picture the difference between the two editions: 1e with its 5% improvement in chances per level until you get to automatic success and 5e with its improvement in chances only through ability score improvements and then a cliff the rest of the way upon reaching the level.
With the types of high level spells you actually care to use from a spell scroll, you’ve got a 50% or higher chance of failure regardless of what level you are with just a 5% benefit here and there from leveling up, if you even make that choice. Meanwhile, the original scroll rules are giving you a 5% better chance every level you progress closer to being able to use the spell.
As an example, in both editions the Clerics and Wizards/Magic-users both gain 3rd level spells at 5th level and 4th level spells at 7th level. Suppose a 5th level cleric from each edition attempts to use a scroll spell of 4th level. The 5th edition Cleric will roll against 14 with a bonus of 3 or 4, so generously he has a 45% chance of failure. The 1st edition Cleric has a 10% chance of failure. They level up the 6th level. The 5th edition Cleric still has a 45% chance of failure, while the 1st edition Cleric has a 5% chance of failure. At 7th level they both have 0% chance of failure. Level 1 might also be illustrative: 5th edition Cleric 50% chance of failure (+3 bonus max at this level), 1st edition Cleric 30% chance of failure for 6 levels lacking.
Anyway, it’s just an odd decision to make scroll usage spike so hard in what is, across most of the range, a massive nerf to spell scrolls in a system where they were already made all but useless by the fact that a full adventuring day almost never leaves the party yearning for more spell slots, even if they aren’t conservative in their use.
None of this ultimately stopped us from acquiring the scroll and working out a way to get advantage and guidance on the check, allowing a much higher chance of success. And of course, the plan backfired in such a way that we might as well have been bluffing about actually having the scroll and now I’ve still got it at the ready for if something else comes up. It’s still a fun game with a lot going for it, but the more I learn about 1e, the more disappointed I become.