I CAST TESTICULAR TORSION

Magic duels are cool. I want them in my game.

What should they look like? They can basically be anything. The way they'll look will be informed by what spells are available in the game and how they work.

As a thought exercise, I started looking over the OSE spell list to see how a theoretical wizard duel might play out following those mechanics as provided, so I could see how one might want to change them to achieve a different result.

I quickly realized that when it comes to wizard duels (and small-scale tactical skirmish combat, the standard use case), the OSE spells are broken as fuck.

The Theory

You have 6 spell levels, theoretically of increasing power.

All spells take 1 slot of their level and are cast the same way--1 full round, damage interrupts, must have a free hand and be able to speak.

This naturally implies that spells of the same level should be roughly equivalent in power, since they have the exact same casting requirements.

Now let's see if that assumption bears out.

The Problem

Hypothetical wizard duel, two magic-users of the same level, both know every spell they're able to cast. I take a look at the classic 1st-level spell list, and these in particular jump out at me as the spells most relevant to wizard duels--though of course a creative wizard might be able to come up with a use for others.

Charm Person: Neutralize a single target (by making them friendly) on a failed save (unreliably, more and more so as the game progresses and saves get better).

Light: Hamper/neutralize a single target (blinding it) on a failed save (unreliably).

Magic Missile: Harm a single target reliably (no save, can't miss).

Protection from Evil: Prevent harm unreliably (makes evil creatures' attacks and spells less likely to hit you, but does nothing to weaken their effects when they do) and situationally (depends on the alignment of your enemies).

Shield: Prevent harm unreliably (better AC means better chance of no damage, but no reduction in damage when someone does hit you).

Sleep: Neutralize multiple targets, reliably (no save), until higher levels at which point it becomes entirely ineffective.

Sleep is vastly overpowered compared to other 1st-level spells. This isn't necessarily a problem. You might want some variation in the power of spells at a given level; I think that makes things more interesting. In Magic: the Gathering, this principle is called the Jedi Curve: when designing a card that costs a given amount to play, the design team maps the "standard" power of a card at that cost as the Jedi Curve, and tries to fill each set with cards that sit above, below, and right on that curve. This is supposed to reward players for learning what cards are good for their cost and seeking out those cards to build their decks around. Similarly, if wizards in your game world know that some 1st-level spells are better than others, they'll be motivated to quest in search of those spells and compete with other wizards to secure copies.

However, I think something like the traditional Sleep is probably too overpowered. Its existence basically destroys the possibility of wizard duels even being a thing; every one will just become a contest to see who can cast Sleep first and win instantly, until you get to duels between wizards with more than 4+1 HD who are just immune to it, which also isn't interesting because it means they can just ignore it completely from then on without having to exercise any kind of competence.

What is it about Sleep that makes it so broken? I set out to understand better. The goal: map an ideal Jedi Curve for my own spell system that manages to account, at least somewhat, for the tactical infinity of OSR play as compared to the strict mechanics of Magic.

The Analysis

So we've already broken down what the most directly fight-related 1st-level spells do, how they're typically going to affect a duel. We can break down the effects of these spells into three categories of sorts, three metrics by which they can be compared. I'm going to call these effectiveness (at offense or defense), scope (how many targets they can affect or threats they can protect against), and consistency (how reliable the effects are).

As we saw, Charm Person, for example, serves to effectively neutralize a target in a fight: it makes the target friendly, causing them to stop fighting, causing the fight to be over and the caster to win. However, it's only effective against a single target, and it's not perfectly reliable, since the target can save against it.

Based on this breakdown, I come up with a few rough scales for each of the categories.

• In terms of effect, we have offensive spells that hamper targets; they weaken them somehow, but not enough to take them out of the fight. Then we have spells that harm targets, bringing them closer to being out of the fight directly. Finally, we have spells that neutralize targets, taking them out of the fight in one fell swoop. Defensively, we have spells that mitigate harm to the caster, making it less severe; spells that entirely prevent harm to the caster; and finally, certain spells might exist to reflect the harm from the caster back at its source.

These don't fully capture the effect of every spell that's useful in a fight, and they're not meant to. For example, you might have two spells that neutralize a target, but one might do so just temporarily, like Sleep, while another makes the subject unable to fight pretty much permanently, like Feeblemind. The second spell is obviously a lot more powerful in general, but in terms of effect on the balance of a single engagement, they're equivalent.

• In terms of scale, we have spells that affect a single target and spells that can affect a whole group.
• And in terms of consistency, we have spells that are unreliable in their effect, because the target can save against them or use some other readily available means to resist them; and then we have spells that are reliable in their effect, those that don't offer a save or any other clear means of resistance.

Both of these are spectrums, of course, not binary categories.

You could also maybe break spells down by duration, like if you have a spell that weakens an enemy just for one round versus a whole fight. Some games do this, but I'm not generally inclined to do it for OSR stuff. In my opinion, when you start designing spells to work only for a certain number of combat rounds--the timescale of a single fight--you're getting away from the kind of tactical philosophy OSR play usually focuses on and more into crunchy skirmish wargame territory. Duration obviously matters on the timescale of an adventure or campaign, but that's not what I'm mostly concerned with when I'm trying to think about how a wizard duel might look in my game.

The Curve

Taking these metrics and applying them to classic spells, I come up with this general outline of what I think a "standard" spell of a given level should be able to do in a wizard duel based on classic OSR-ish spells. This goes up to 5th level, which is kind of the breakpoint where I like to think spells are more about affecting domain-scale stuff rather than personal adventuring.

1st Level

Hamper a single target reliably. This could be something like a blinding Light spell, if the target doesn't get a save.

Hamper a group unreliably. Something like a Fog Cloud, which has the obvious downside of also hampering your allies at close range.

Harm a single target reliably. This is your Magic Missile, the easiest balance point to compare magical forms of attack with physical; it's a bowshot that can't be dodged, but consumes whatever resources it takes to cast a spell (often much more limited than arrows) and might be interruptible depending on if you have all your spells take a full round.

Neutralize a single target unreliably. I might do this as a single-target version of Sleep that allows a save or some other countermeasure; perhaps a droning speech that can lull an unsupecting subject to unconsciousness, but they can stop their ears if they get wise early.

Block harm from a single threat unreliably. This is your standard Shield, easy enough.

2nd Level

Hamper a group reliably. Your Web.

Harm a group unreliably. Burning Hands, perhaps--blast a bunch of fools at once, but they can dodge.

Block harm from a single target reliably. This could be your Mirror Image. A group attacking you all at once could hit all the dupes at once and isolate the real you.

3rd Level

Harm a group reliably. Here you get your Fireballs and Lightning Bolts. Even if your opponents save, they're still getting at least somewhat fucked up.

Neutralize a single target reliably. Hold Person, assuming either no save or a difficult one.

Mitigate harm from a group reliably. Magic Armor; you're tougher, but they can still get through, or it only reduces harm rather than stopping it even when it works.

4th Level

Neutralize a group unreliably. This could be a Confusion; maybe it allows a save, or maybe it's always effective but doesn't always stop subjects from being dangerous.

Block harm from a group unreliably. Protection from Normal Missiles fits this; always good against arrows, does nothing for melee weapons.

5th Level

Neutralize a group reliably. This is Cloudkill, with the "weak enemies die outright."

Block harm from a group reliably. Protection from Normal Weapons, check.

Closing Thoughts

I notice the parameters actually get narrower and narrower at each level. That might feel counterintuitive, but I actually think it makes sense. Personal-scale combat is a pretty niche scenario in a good OSR game, and I think a good magic system should be about much more than that overall. If there are fewer and fewer tactical niches for higher-level spells in that scenario, it suggests that a greater proportion of spells at each ascending level are mainly focused on other things, operating at larger scales where the greater number of situational factors at play makes their utility harder to measure and compare. 

Is this useful? I dunno, I feel like it will be for me. It's something I can look at when I want to make a new spell to get a sense of how it might or might not fuck up my wizard fights. Having a reference like that will help me get over my analysis paralysis. Maybe it'll be useful for some of you too.