Tuesday, May 05, 2026

Poison in Original D&D: Can This Be Right?

It's fair to say that original Dungeons & Dragons can be a bit hard to parse sometimes, and there are aspects of the rules as written that are ambiguous.  Most of those have been hashed out online over the last couple of decades (boy, have they...), but there's a passage in the rules regarding poison that I don't think I've ever seen discussed.  It's the paragraph right after the saving throw tables (spanning page 20-21 of Volume 1: Men & Magic).  I'll reproduce it below:

"Failure to make the total indicated above results in the weapon having full effect, i.e. you are turned to stone, take full damage from dragon's breath, etc. Scoring the total indicated above (or scoring higher) means the weapon has no effect (death ray, polymorph, paralization, stone, or spell) or one-half effect (poison scoring one-half of the total possible hit damage and dragon's breath scoring one-half of its full damage)."

At first glance, this is just describing the standard saving throw procedure we all know and love: your character gets hit with an attack, you roll 1d20 against a target number, and if you roll high enough the effect is either negated or lessened depending on its nature.  As someone very familiar with later versions of these rules, it's easy to skim over this material without taking in what it actually says.  I know I read this passage many times before the bit about poison jumped out at me as unusual.  Let's circle back to it, because I think it works a little differently to poison saving throws in later D&D editions.

The relevant passage is this: "poison scoring one-half of the total possible hit damage".  Later editions (particularly Advanced D&D) usually treat poison as an all-or-nothing affair; either your character makes their saving throw and lives, or fails it and dies.  This line in original D&D suggests something different.  "Total possible hit damage" has to refer to the victim's total hit points, yes?  That's how I read it.  So in original D&D it appears to me that, on a failed saving throw, poison deals damage equal to the victim's total hit points, killing them in the familiar manner.  But on a successful save, rather than the poison being avoided or negated, it deals damage equal to half of the victim's total hit points.

It seems to me that this is the correct interpretation, and it makes poison quite a bit more dangerous.  The main thing that's up for interpretation is whether a failed save deals damage equal to half of a character's total hit points, or their current hit points.  I'm inclined to go with the latter interpretation, just because it favours the players.  A strict reading favours using the "total hit point" interpretation, but I'd rather not have player characters dying on successful saving throws if I can help it.  Yes, I know it can happen with fire balls and the like, but I'd rather not add yet another way for the PCs to die horribly.

I'd be interested in what my readers think. Have any of you noticed or used this interpretation of the rules before?  Any thoughts or war stories are appreciated.