I suppose I’m on the hook now, having been mentioned on both Delta’s blog and Grognardia.  Actually, Delta and I already discussed doing these posts based on the evolution of individual spells through the various editions of D&D, and I’m totally on board.  I’m going to try and stick to clerical spells, as Delta doesn’t use clerics in his game, it should make it easy to avoid collisions.  However, today’s spell is on both lists, so I want to get it out there before Delta does.  🙂

One can’t really analyze the spell Detect Evil without also looking at the changes in the alignment system over the course of the different editions.  I’ll touch on those briefly, but I’ll leave it to the reader to dig up more specifics on the differing alignments systems.  So let’s begin with the beginning, the spell as it appears in OD&D (vol. I, page 24):

Detect Evil: A spell to detect evil thought or intent in any creature or evilly enchanted object. Note that poison, for example, is neither good nor evil. Duration: 2 turns. Range: 6″.

This is the level 2 magic-user version.  The level 1 clerical spell differs only in range (12″) and duration (6 turns).  Interesting though that the cleric version gets a boost in both, despite being lower level.  Also interesting to note, the Holmes version is pretty much identical, despite the change in alignment system.  OD&D uses the original single axis alignment of Chaos, Neutrality, and Law.  Holmes introduces the second axis of Good vs. Evil, but does not have variations of neutrality (no Neutral Good or Chaotic Neutral, for example).

Now OD&D doesn’t give us real direction on what is evil.  Holmes however, clearly tells us in monster descriptions whether they are evil via their alignment.  So the question is, in OD&D are chaotic creatures evil?  Well, let’s take a look at the B/X version of the spell, which also has the single-axis alignment system (Basic Book, page B15) :

Detect Evil Range: 120′, Duration 6 Turns

This spell can be used to detect evil intentions, or evilly enchanted objects within
120′ causing the creatures or objects to glow. Actual thoughts are not detected; only the “feeling of evil”. The exact definition of “evil” is left to each referee, and players should discuss this point so that all are in agreement; “Chaotic” is not always “evil”. Poison and physical traps are neither good nor evil.

Well, looks like it was already becoming a contentious issue.  Here we see that chaotic and evil are clearly not equal, and the entire thing is left to the DM to decide.  Moldvay wipes his hands of the issues, and tells the DMs: “you figure it out.”  But here’s an interesting twist, Moldvay tells us that this spell does not read the evil creature’s thoughts, and we only get a sense of evil.  Is this in opposition to the earlier verbiage?  Clearly the old description mentions detecting “evil thought”, but does that just mean that we know someone is having evil thoughts, or can we hear the thoughts themselves, a la an ESP spell?  I suspect the former, and I suspect misinterpretation of this resulted in a lot of teeth gnashing around the gaming tables.

Here’s the 1st Edition version to muddy the waters further (Player’s Handbook, page 44):

Dtect Evil (Divination) Reversible

Explanation/Description: This is a spell which discovers emanations of evil, or of good in the case of the reverse spell, from any creature or object. For example, evil alignment or an evilly cursed object will radiate evil, but a hidden trap or an unintelligent viper will not. The duration of a detect evil (or detect good) spell is 1 turn + 1/2 turn (5 rounds, or 5 minutes) per level of the cleric. Thus a cleric of 1st level of experience can cast a spell with a 1 1/2 turn duration, at 2nd level a 2 turn duration, 2 1/2 at 3rd, etc. The spell has a path of detection 1” wide in the direction in which the cleric is facing. It requires the use of the cleric’s holy (or unholy) symbol as its material component, with the cleric holding it before him or her.

Now we are detecting “emanations” of evil, clearly not thoughts nor intent.  And for the first time, the spell distinctly references the alignment system.  From this version forward, we’ll see this spell is always locked into a an alignment detection spell.  But wait, don’t we have a separate spell for that?  Indeed, it’s on the very next page of the PHB, Know Alignment, a 2nd level clerical spell.

By 3e and later the spell becomes increasingly complex.  So much so that I’m not going to post all the charts that go with it, but you can check them out yourself over on the Hypertext SRD.  Suffice it to say that the alignment hook is firmly in place by now, the spell has been broken out to a version for each alignment leaf node (Detect Evil, Detect Good, Detect Law, and Detect Chaos), and Know Alignment is gone.  Also, we get some very specific tables about what kind of creatures or objects emanate various strengths of evil auras.

I’m not posting a poll with this one, sorry everyone.  I know how I rule this one, and I sort of think Moldvay got it right.  It could be because I run B/X, or it could be because I see this spell as more of a plot hook spell than some kind of tactical bad-guy finder, but I happen to think this really is a case where the DM simply must figure it out for himself.  What is evil?  That’s a pretty philosophical question.  I can tell you how it works in my own game though:

I play the alignments fairly literally.  Either you’re in league with the forces of law, or the forces of chaos, or you just don’t care about the struggle (Neutrality).  Being chaotic isn’t just bucking the system, it’s trying to destroy everything that’s good, let loose the demons from the gates of hell, and purge the world of all that is right and good, or at least enslave them and rule them with an iron fist.  Chaotic people/creatures are just plumb bad, in fact, you might say evil.  Does a goblin radiate evil in my game?  You bet he does.  And he’ll prove it by gutting any of you surface dwellers any time he gets half a chance.

That’s my take on it.  Is it the right interpretation?  I don’t think there is such a thing.  Each DM has got to play it the way it best fits in his campaign.  Unfortunately, I don’t think the writers/editors of later editions really trusted their DM readers to make those kind of choices.