To counter a spell, expend one prepared spell and follow the formula presented for dispell magic:
Dispell Magic: Unless countered, this spell will be effective in dispelling enchantments of most kinds (referee’s option), except those on magical items and the like. This is modified by the following formula. The success of a Dispell Magic spell is a ratio of the dispeller over the original spell caster, so if a 5th level Magic-User attempts to dispell the spell of a 10th level Magic-User there is a 50% chance of success. Duration: 1 turn. Range: 12″.
Source: Men & Magic, page 25.
That is, any prepared spell can be “converted” into an antagonistic dispell magic. One could without issue probably extend that to full dispell magic functionality (thereby doing away with the need to find, learn, or prepare dispell magic as a distinct spell), given that removing enchantments is a relatively core aspect of wizarding, though I could understand wanting to keep the full dispell magic a separate thing.
Note that OD&D does this differently than AD&D, which works like the BRP resistance table (50% success modified by level differential). To make the difference clear, in OD&D a 9th level magic-user has a 90% chance of successfully dispelling an 10th level magic-user’s enchantment (9/10), while in AD&D the chance would be only 45% (50% -5% for having one less level).
Alternatively, compare spell levels rather than class levels using the OD&D formula. So, expending a second level spell in an attempt to counter a third level spell would have a 2/3 (66%) chance of success. This method might be preferred if you see the countering process as an opposition of specific spell energies rather than a contest between the overall skill of the two magic-users.
The burn spells paradigm is becoming increasingly attractive to me. There is some danger of complexity creep, so the possibilities should be limited to a small number of effects. That said, having several default options frees up magic-users to prepare more obscure or interesting spells, which otherwise might not get as much use, much as 3E clerics were able to convert any spells into cures. Further, requiring the expenditure of prepared spells to power such effects retains some degree of resource constraint, unlike make other unlimited or at-will approaches, and doesn’t require tracking any additional information, since spell slots are already managed.
The options so far that I have thought about are maleficence, magical defense, and now dispell magic. I could see adding read magic to that list perhaps, though I am also experimenting with replacing read magic with a “skill” type d6 roll that comes at the cost of an exploration turn.
(This idea came to me when I repurposed dispell magic for banishing summoned creatures.)
Thieves can cast from scrolls as a skill; it seems to be a short step to allowing actual wizards to be able to read the things without a spell.
Read magic as a skill is something I have experimented with as well. I call this the Runes Expert Skill currently in The Final Castle, and using it requires spending a dungeon turn, just like other Expert Skills.
That said, I do not think the read magic spell is as useless as commonly held, but its use does depend heavily on scenario design. I have come to enjoy placing many hazards or tricks that read magic can be useful for. Giant steles or slabs of stone with inscribed magic (basically, unportable scrolls). Or warding runes that can be understood but not triggered with read magic. And so forth. Control words for magic items are another idea. OD&D does not have an identify spell, for example. Why not give read magic that functionality as well?
Making read magic take a slot means that magic-users need to choose between being prepared for such occurrences or taking other spells, which is an interesting tradeoff if your scenarios do in fact have other uses for read magic. One excursion might locate a point of interest to investigate with read magic in the future, giving added value to information gathering.
I’ve done away with Read Magic in Necrocarcerus by folding it into a more general Decipher skill that also covers breaking codes and translating lost languages (as opposed to ones PCs can learn) with the d6/d8/d10/d12 skill progression. I’ve been very happy with the results. If I weren’t already using this skill system, I think having Read Magic work like a Thief’s Hear Noise skill would be ideal (I also think Detect Magic and learning new spells should work the same way).
The dispel balance seems like it might produce percentages that are a bit higher than I prefer, but that might be intentional since one is burning a spell slot for it?
Yeah, I think it is reasonable that the percentages are rather high given the resource cost. In general, I tend to be somewhat unsatisfied when expending resources can have entirely no effect (many spells that provide saves have this character), and lean towards rulings of partial effects (drowsiness even on a successful save against sleep, and so forth).
This may be unintentional or it may be a misreading on my part, but it reads like the first option lets me expend a 1st level slot to dispel any spell, since its actual success is based only on class level. That’s why the success percentage appears high to me. You expend a 3rd level slot, I expend a 1st level slot, but because I’m level 9 to your level 6, there’s a 150% chance of my dispel working. Because I have more slots, and can expend my lowest level ones first to counter your spells, this means that, ceter paribus, high level wizards will almost always beat lower level ones by exhausting their spell slots.
high level wizards will almost always beat lower level ones by exhausting their spell slots
That’s good, right? I kind of like how it makes low level spell slots useful to high level wizards. It seems like high level wizards should be able to wear down lower level wizards through attrition.
Though yeah, there are a lot of potential unintended consequences here. Might high level wizards never cast mending or light because of the potential value as counter-spells?
Using the spell slot level comparison rather than class level comparison gets around that problem though, if one thinks it is a problem.
Consider: spell slots could be thought of almost as magic HP.
If spell slots can be exchanged for other spells, what is the in-game explanation for this phenomenon?
Spells as extradimensional entities fighting is probably what I would use, but it really depends on how you see magic a particular setting. Using the energies of one spell to counteract another would be another way to think about it.
Pingback: Magic Monday – opening thoughts | landofnudotcom
Pingback: Magic Monday: Undoing | landofnudotcom
Would this version of Dispell supersede your magical defense idea? Why defend two or three friends when you can just dispel the offending spell?
You could restrict this version of Dispell to countering an actual spell being cast and say magical defense is the only way to counter Maleficence. If the attacking wizard let’s the raw, unfocused energy of a spell loose, the defending wizard can only protect a few friends. If the attacking wizard sticks to the orderly, intended release of a spell, you can simply counter it with a Dispell.
Have to play it that way a few times, I’m sure there’s a down-side I haven’t thought of…
As proposed here, dispell has a chance of failure (depending on the relative strengths of the two magicians), while magic shield does not.
Also, dispell could be used against a non-threatening spell. Or, perhaps more precisely, a spell without a target. What if a magic-user is conjuring an elemental? Using a shield to protect against that does not really make sense, but the summon itself could be countered (for example).