This past week, my D&D group found itself in battle with a monster made out of blood. We defeated it, though it drained more than the proverbial 75% of party resources. As the fight began, I found myself thinking that there was another way we could be dealing with this situation that, had the storyteller allowed it, could have ended the battle almost instantly. Bear with me for a moment and you'll see where I'm going.

You see, the party's witch has a viper for her familiar. We don't know exactly what type of viper, which is nobody's fault but Wizards of the Coast. Having gone through medical school, my slightly-above-average brain is chock full of all sorts of useless knowledge, including a very superficial understanding of how snake venom works... I'm no expert, since Canada isn't a place where we need a thorough mastery of how to treat snakebite, but I learned the basics while writing American practice exams. I'll explain in a bit more detail below, but first, here's a graphic depiction. Go to YouTube and type in "effect of snake venom on blood," or anything reasonably close to that. YouTube, being the godlike omniscience that it is, will bring up countless videos showing what happens if you add a minute amount of venom to a jar or a dish or a bowl full of blood. You see? It's impressive. As we geared up for the fight, I made a heroic effort to persuade the storyteller that we wanted to milk a bit of the familiar's poison (we had the necessary tools), put the venom into a test tube, tie it to an arrow, and shoot the blood monster with it. I argued that this should be, if not instantly fatal to it, then at least very unpleasant. My storyteller, unfortunately, didn't allow it, on the grounds that the rulebooks had no mechanics to cover this situation and so he didn't know how to handle it... which is either a weakness of my gaming style or his, depending on who you ask.

For those of you who don't want to watch the aforementioned videos, or who want a bit of a description of why venom does what it does, keep reading. It's cool, in a useless, trivia-geek sort of way.

In the interest of disclosure, what follows is not stuff that I knew off the top of my head. I had to look it up just now. UpToDate, one of the most popular physician resource websites in the world, has no less than three articles devoted to snakebite, as well as a number of other articles where snake venom is at least briefly mentioned: one on snakebite in general, one on the Crotalinae family (which includes rattlesnakes, water moccasins, cottonmouths, and copperheads, and one on Elapidae, which includes the coral snake. The first article deals with worldwide data -- snakebite being one of the major health problems in much of the world, and therefore quite probably in a fantasy campaign setting -- while the two more specific articles are targeted towards the United States. Also, you should know that I'm a snake phobic, so reading these articles creeped the hell out of me and I still did it. Hooray for exposure therapy!

Worldwide, about 125,000 die from snakebites per year. I don't know how many people actually die in the world every year, but that sounds like a lot to me. In the United States, about 8000 bites are reported per year, causing only about 10-15 deaths. It should be noted that the exact species of snake makes a huge difference. Some species' venom causes rapid damage to the nervous system and relatively little coagulation of the blood, while others mostly cause breakdown of local tissues. Understandably, this means envenomation should have very different in-game effects and very different treatments (never, ever apply local pressure to a cobra bite). Put simply, different venoms can be divided into a few categories.

Neurotoxic venoms attack the nervous system. Australians snakes tend to have this sort of venom, which is nice if you live in Australia because, although they're incredibly lethal, they're relatively painless. The first symptom after envenomation is often blurry or double vision, followed by difficulty speaking, and weakness or paralysis. Death occurs if the respiratory muscles become paralyzed.

Coagulopathic venoms are the ones you probably saw if you went to YouTube. These venoms cause the blood to start coagulating and clotting inside your veins. Other coagulopathic venoms may actually prevent the blood from clotting, causing excessive bleeding and internal haemorrhage, but the clinical symptoms are similar. The victim may start bleeding from their gums, and often from the bite site. Death often occurs due to stroke, either from clots going to the brain or from intracranial bleeding.

Rhabdomyolytic venoms directly act to break down tissues that they come in contact with. As you can probably imagine, this is a "bad thing." I won't go into detail... suffice it to say that if death occurs, it's often due to a combination of damage to the brain, the heart, and the kidneys.

Pretty much all venoms also have some general effects: they cause the veins to dilate excessively, so that blood pressure drops; many cause direct damage to the heart muscle; most cause some degree of nausea, vomiting, or headache; and almost all damage the kidneys, through a variety of mechanisms, which can lead to death weeks, months, or years later under some circumstances. On top of everything else, a snakebite can also cause an infection, because snakes rarely brush their teeth. Different snakes in different parts of the world seem to have different rates of causing infections; in Brazil, about 10% of snakebites lead to an infection requiring antibiotics, while in other countries post-bite infection seems to be much less common. The bites can also cause tetanus, which seems like a small problem in comparison but needs to be remembered.

In the case of my D&D game, the witch's familiar was a viper, which means that its venom *probably* worked primarily by causing necrosis of nearby tissue. This should, by all rights, have been beautifully effective against the blood monster. 

A little more than four years ago, Dr. Eris Lis, M.D., began writing a series of brilliant and informative posts on RPGs through the eyes of a medical professional, and this is the one that appeared here on April 27, 2013. Lis is a physician, gamer, and author of the Skirmisher Publishing LLC OGL sourcebook Insults & Injuries, which is also available for the Pathfinder RPG system.